Membranes for electrochemical cells

ABSTRACT

Ionically conducting composite membranes are provided which include a solid-state ionically conducting material The ionically conducting composite membranes may be used in electrochemical cells. The solid-state ionically conducting material may be an electrochemically active material. In some electrochemical cells, the solid-state ionically conducting material may be in electronic communication with an external tab.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of priority from U.S.Provisional Application No. 61/976,281, filed Apr. 7, 2014 and is acontinuation-in-part application U.S. patent application Ser. No.14/546,953, filed Nov. 18, 2014, which claims the benefit of priority toU.S. Provisional Application No. 61/905,678, filed Nov. 18, 2013; U.S.Provisional Application No. 61/938,794, filed Feb. 12, 2014; U.S.Provisional Application No. 61/985,204, filed Apr. 28, 2014 and U.S.Provisional Application No. 62/024,104, filed Jul. 14, 2014 all of whichare incorporated herein by reference in their entireties and is acontinuation-in-part application of International Patent Application No.PCT/US14/66200, filed Nov. 18, 2014, which claims the benefit ofpriority to U.S. Provisional Application No. 61/905,678, filed Nov. 18,2013; U.S. Provisional Application No. 61/938,794, filed Feb. 12, 2014;U.S. Provisional Application No. 61/985,204, filed Apr. 28, 2014 andU.S. Provisional Application No. 62/024,104, filed Jul. 14, 2014.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND

Over the last few decades revolutionary advances have been made inelectrochemical storage and conversion devices expanding thecapabilities of these systems in a variety of fields including portableelectronic devices, air and space craft technologies, passenger vehiclesand biomedical instrumentation. Current state of the art electrochemicalstorage and conversion devices have designs and performance attributesthat are specifically engineered to provide compatibility with a diverserange of application requirements and operating environments. Forexample, advanced electrochemical storage systems have been developedspanning the range from high energy density batteries exhibiting verylow self-discharge rates and high discharge reliability for implantedmedical devices to inexpensive, light weight rechargeable batteriesproviding long runtimes for a wide range of portable electronic devicesto high capacity batteries for military and aerospace applicationscapable of providing extremely high discharge rates over short timeperiods.

Despite the development and widespread adoption of this diverse suite ofadvanced electrochemical storage and conversion systems, significantpressure continues to stimulate research to expand the functionality ofthese systems, thereby enabling an even wider range of deviceapplications. Large growth in the demand for high power portableelectronic products, for example, has created enormous interest indeveloping safe, light weight primary and secondary batteries providinghigher energy densities. In addition, the demand for miniaturization inthe field of consumer electronics and instrumentation continues tostimulate research into novel design and material strategies forreducing the sizes, masses and form factors of high performancebatteries. Further, continued development in the fields of electricvehicles and aerospace engineering has also created a need formechanically robust, high reliability, high energy density and highpower density batteries capable of good device performance in a usefulrange of operating environments.

Many recent advances in electrochemical storage and conversiontechnology are directly attributable to discovery and integration of newmaterials for battery components. Lithium battery technology, forexample, continues to rapidly develop, at least in part, due to thediscovery of novel electrode and electrolyte materials for thesesystems. The element lithium has a unique combination of properties thatmake it attractive for use in an electrochemical cell. First, it is thelightest metal in the periodic table having an atomic mass of 6.94 AMU.Second, lithium has a very low electrochemical oxidation/reductionpotential (i.e., −3.045 V vs. NHE (normal hydrogen referenceelectrode)). This unique combination of properties enables lithium basedelectrochemical cells to have very high specific capacities. State ofthe art lithium ion secondary batteries provide excellentcharge-discharge characteristics, and thus, have also been widelyadopted as power sources in portable electronic devices, such ascellular telephones and portable computers. U.S. Pat. Nos. 6,852,446,6,306,540, 6,489,055, and “Lithium Batteries Science and Technology”edited by Gholam-Abbas Nazri and Gianfranceo Pistoia, Kluer AcademicPublishers, 2004, which are hereby incorporated by reference in theirentireties, are directed to lithium and lithium ion battery systems.

Advances in electrode materials, electrolyte compositions and devicegeometries continue to support the further development of Li basedelectrochemical systems. For example, U.S. Patent ApplicationPublication US2012/0077095, published on Mar. 29, 2012, andInternational Patent Application publication WO 2012/034042, publishedon Mar. 15, 2012, disclose three-dimensional electrode array structuresfor electrochemical systems including lithium batteries.

As will be generally recognized from the foregoing, a need currentlyexists for electrochemical systems, such as lithium based or alkalinebased batteries, flow batteries, supercapacitors and fuel cells,exhibiting electrochemical properties useful for a range ofapplications. Specifically, lithium electrochemical systems capable ofgood electrochemical performance and high versatility for both primaryand secondary lithium based batteries are needed.

SUMMARY

In an aspect, the invention provides an ionically conducting compositemembrane which includes a solid-state ionically conducting material. Themembranes provided by the present invention can be used inelectrochemical cells. Use of a solid-state ionically conductingmaterial in the composite membrane can seal one portion of the cell fromanother. For example, use of such an ionically conductive membrane canallow use of an aqueous electrolyte in contact with one electrode and anon-aqueous electrolyte in contact with another electrolyte. In otheraspects, the invention provides electrochemical cells including theionically conducting composite membranes and methods for using theelectrochemical cells. In embodiments, the electrochemical cell is aLi-ion or Na-ion cell

Solid-state ionically conducting materials conventionally used aselectrolytes include gelled polymers, solvent free polymers, inorganiccrystalline compounds and inorganic glasses. In an embodiment,solid-state ionically conducting materials include materials whichinclude materials whose ionic conductivity is electronically“activated”, such as by application of voltage or current. Inembodiments, the applied current or voltage can be direct or alternating(e.g. a sinusoidal voltage). In an embodiment, such a material has asignificantly greater ionic conductivity in the “activated” state; useof such a material can provide gating functionality.

In a further embodiment, solid-state ionically conducting materialssuitable for use in the composite membranes disclosed herein includematerials conventionally used as active materials in electrochemicalcells. Such a material may be “activated” by application of a voltagevarying between the charge-discharge voltage of the electrolyte. In anembodiment, such a solid-state ionically conductive material is an oxidematerial, such as lithium titanate or titanium dioxide. In anotherembodiment, the solid-state ionically conductive material is asemiconductor, such as silicon. In another embodiment, the solid-stateionically conductive material is a conventional carbonaceous anodematerial such as graphite, modified graphite, and non-graphitic carbons.In a further embodiment, one or more of these materials conventionallyused as electrochemically active materials is used in combination withone or more conventional solid electrolyte materials. Benefits of suchcells include, but are not limited to higher mechanical flexibility ofthe cell during manufacturing and operation, ease of manufacturing,allowing different materials with better thermal and mechanicalstability to be used, slowdown of the migration of active materialsbetween the electrodes and lower impedance between the electrodes andthe membrane which results in faster rates and longer cycle life. Insome embodiments where the electronchemically active materials are inelectrical communication with an external tabl, active materialadditives may be released to the cell when needed.

In embodiments, the solid-state ionically conductive material is in theform of a free standing layer, a coating layer, or included in a supportor frame of an electronically conducting or electronically insulatingmaterial (e.g. a material which does not conduct electrons through thethickness of the support). Supported solid electrolyte material may bein the form of bulk pieces, particles or fibers. Particles or fibers ofsolid electrolyte material may be combined with other materials suchbinders and/or conductive particles or fibers. The support or frame mayprovide high mechanical strength to the layer including the solid-stateionically conductive material. In an embodiment, the composite membranehas a shear modulus from 1 GPa-3 GPa, a tensile strength of 100-300 MPaand a rupture strength of 900 to 1100 gr.

The ionic conductivity of the composite membrane may be greater than 1mS/cm In an embodiment, for example, the composite membrane in thepresence of an appropriate electrolyte provides a net ionic resistancefrom the positive electrode to the negative electrode selected over therange of 0.5 ohm cm² to 25 ohm cm², and preferably for some applicationsless than 5 ohm cm².

In an additional aspect, the solid-state ionically conductive materialis in electronic communication with an external connection tab. Theexternal connection tab may also be referred to as an external tab. Inan embodiment, the external connection tab used to modify theperformance of the cell by applying a voltage or current between theexternal connection tab and either the external connection tab of one ofthe electrodes or of an additional electronically conductive layer inthe composite separator

In an aspect, the disclosure provides an electrochemical cell comprisinga positive electrode, a negative electrode and a composite membranedisposed between the positive electrode and the negative electrode, thecomposite membrane comprising a layer comprising a solid-state ionicallyconductive material. In an embodiment, the cell further comprises atleast one liquid electrolyte disposed between the composite membrane andeach of the positive and the negative electrodes and the compositemembrane comprises a porous or perforated electronically insulatingseparator layer disposed between the layer comprising the solid-stateionically conductive material and each of the positive and the negativeelectrode. In an embodiment, the positive electrode comprises a positiveelectrode active material and a first current collector in electroniccommunication with the positive electrode active material, the firstcurrent collection further comprising a first external connection tab, anegative electrode comprising a negative electrode active material and asecond current collector in electronic communication with the negativeelectrode active material, the second current collector furthercomprising a second external connection tab and the ionically conductivesolid-state material being in electronic communication with a thirdexternal connection tab. In an embodiment, the solid-state ionicallyconductive material is electronically “activatable” so that applicationof a voltage between the third external tab and any of the electrodesproduces a significant increase in the ionic conductivity of thematerial.

In an embodiment, the invention provides an electrochemical cellcomprising:

-   -   a positive electrode comprising a positive electrode active        material and a first current collector in electronic        communication with the positive electrode active material, the        first current collection further comprising a first external        connection tab;    -   a negative electrode comprising a negative electrode active        material and a second current collector in electronic        communication with the negative electrode active material, the        second current collector further comprising a second external        connection tab;    -   a composite membrane disposed between the positive electrode and        the negative electrode; the composite membrane being ionically        conductive and comprising        -   an ionically conductive solid-state material in electronic            communication with a third external connection tab;        -   a first ionically conductive separator positioned between            the positive electrode and the composite membrane; and        -   a second ionically conductive separator positioned between            the negative electrode and the composite membrane; and    -   one or more electrolytes positioned between said positive        electrode and said negative electrode; said one or more        electrolytes capable of conducting ionic charge carriers.

In a further embodiment, the composite membrane further comprises athird current collector in electronic communication with ionicallyconductive solid-state material, the third current collector beingporous or perforated

In an aspect, the disclosure provides an electrochemical cell comprisinga positive electrode, a negative electrode and a composite membranedisposed between the positive electrode and the negative electrode, thecomposite membrane comprising a layer comprising a solid-state ionicallyconductive material. In an embodiment, the solid-state ionicallyconductive material is material conventionally used as an activematerial in a positive or negative electrode material. In an embodiment,the cell further comprises at least one liquid electrolyte disposedbetween the composite membrane and each of the positive and the negativeelectrodes and the composite membrane comprises a porous or perforatedelectronically insulating separator layer disposed between the layercomprising the solid-state ionically conductive material and each of thepositive and the negative electrode.

In an embodiment, the invention provides an electrochemical cellcomprising:

-   -   a positive electrode;    -   a negative electrode;    -   a composite membrane layer comprising        -   a layer comprising an ionically conductive and            electrochemically active solid-state material;        -   a first ionically conductive porous separator positioned            between the positive electrode and the membrane layer;        -   a second ionically conductive porous separator positioned            between the negative electrode and the membrane layer; and    -   one or more electrolytes positioned between said positive        electrode and said negative electrode; said one or more        electrolytes capable of conducting ionic charge carriers. In an        embodiment, the porous separators are electronically insulating.

In a further embodiment, the invention provides an electrochemical cellcomprising:

-   -   a positive electrode;    -   a negative electrode;    -   a composite membrane layer positioned between the said        electrodes comprising        -   at least one porous separator layer;        -   at least one ionically conductive and electrochemically            active solid-state material; and            one or more electrolytes positioned between said positive            electrode and said negative electrode; said one or more            electrolytes capable of conducting ionic charge carriers

In an additional embodiment, the invention provides an electrochemicalcell comprising:

-   -   a positive electrode;    -   a negative electrode;    -   a composite porous separator layer positioned between the said        electrodes comprising        -   at least one ionically conductive and electrochemically            active solid-state material, and        -   at least one solid-state binder material; and    -   one or more electrolytes positioned between said positive        electrode and said negative electrode; said one or more        electrolytes capable of conducting ionic charge carriers.

In a further embodiment, the active layer further comprises a tab whichallows connection of the layer comprising the ionically conductive andelectrochemically active solid-state material to another electrode or toa source of current or voltage. In an embodiment, an active layer actsas an auxiliary electrode when an external tab is in electroniccommunication with the active layer. In an addition embodiment, theactive layer further comprises electronically and ionically conductivelayer in electronic contact with the electrochemically active materialof the layer.

In an embodiment, the invention provides an electrochemical cellcomprising:

-   -   a positive electrode comprising a positive electrode active        material and a first current collector in electronic        communication with the positive electrode active material, the        first current collection further comprising a first external        connection tab;    -   a negative electrode comprising a negative electrode active        material and a second current collector in electronic        communication with the negative electrode active material, the        second current collector further comprising a second external        connection tab;    -   a composite membrane disposed between the positive electrode and        the negative electrode; the composite membrane being ionically        conductive and comprising        -   an ionically conductive solid-state material in electronic            communication with a third external connection tab;        -   a first ionically conductive separator positioned between            the positive electrode and the composite membrane; and        -   a second ionically conductive separator positioned between            the negative electrode and the composite membrane; and    -   one or more electrolytes positioned between said positive        electrode and said negative electrode; said one or more        electrolytes capable of conducting ionic charge carriers. In an        embodiment, the separator is electronically insulating.

In a further embodiment, the invention provides an electrochemical cellcomprising:

-   -   a positive electrode comprising a positive electrode active        material and a first current collector in electronic        communication with the positive electrode active material, the        first current collection further comprising a first external        connection tab;    -   a negative electrode comprising a negative electrode active        material and a second current collector in electronic        communication with the negative electrode active material, the        second current collector further comprising a second external        connection tab;    -   a composite membrane disposed between the positive electrode and        the negative electrode; and comprising        -   an ionically and electronically conductive layer;        -   at least one electronically insulating porous layer            positioned between the said electronically conductive porous            layer and an electrode.    -   one or more electrolytes positioned between said positive        electrode and said negative electrode; said one or more        electrolytes capable of conducting ionic charge carriers.

In an embodiment, the disclosure provides an electrochemical cellcomprising: a positive electrode; a negative electrode; one or moreelectrolytes positioned between said positive electrode and saidnegative electrode; said one or more electrolytes capable of conductingionic charge carriers; and a composite membrane comprising at least twoelectronically insulating and ionically conductive layers; said membranepositioned between said positive electrode and said negative electrodesuch that said ionic charge carriers are able to be transported betweensaid positive electrode and said negative electrode but not electroniccharge carriers. In an embodiment, at least one of the electronicallyinsulating and ionically conductive layers comprises a solidelectrolyte.

In some aspects, the invention provides composite membranes and membranesystems for use in an electrochemical cell and electrochemical cellscomprising these membrane systems. In an embodiment, the compositemembrane comprises a first membrane layer comprising a solid or gelelectrolyte disposed within the apertures of a support structure and asecond membrane layer comprising a plurality of pores, the pores of thesecond membrane layer being offset from the apertures of the firstmembrane layer. FIG. 1 illustrates an exemplary first membrane layer 20including a support structure 22 and apertures 24. FIG. 2 illustrates anexemplary second membrane layer 30 comprising pores 34; when these twolayers are placed in contact, the pores of the second layer are offsetfrom the apertures of the first membrane layer. In an embodiment thefirst membrane layer is a high mechanical strength layer. In a furtherembodiment only one high mechanical strength layer is present in themembrane system and that high mechanical strength layer is the firstmembrane layer. In an embodiment, the second membrane layer may be aporous or perforated polymeric separator. In the embodiment, the size ofthe apertures of the first membrane layer are greater than the size ofthe pores of the second membrane layer, as schematically illustrated inFIGS. 1 and 2. In embodiments, the ratio of the size of the apertures tothe size of the pores is from 5:1 to 100:1, from 5:1 to 20:1, from 25:1to 100:1 or from 25:1 to 50:1. In embodiments, the aperture size is from5 nm to 2 mm, 10 nm to 1 mm, from 1 mm to 10 mm, or from 500 μm to 1 mmand the pore size is from 5 nm to 2 mm, 10 nm to 1 mm, from 100 μm to500 μm or from 10 μm to 50 μm.

In a further embodiment, the second membrane layer further comprises anelectronically conductive coating on one side of the layer. In anembodiment, the electronically conductive coating is on the electrodeside of the layer. In an further embodiment an external tab is connectedto this electronically conducting layer; in this embodiment theelectronically conductive coating may be on either side of the membrane.

In an embodiment, the first membrane layer is disposed proximate to thepositive electrode and a liquid electrolyte is provided proximate to thenegative electrode. In an embodiment, the liquid electrolyte at leastpartially fills the pores of the second membrane layer. In a furtherembodiment, a second electrolyte is provided between the positiveelectrode and the first membrane layer.

In an embodiment, the solid electrolyte is provided within a layerinside the apertures and the thickness of the layer is from 0.01 mm to0.5 mm or from 5 μm to 20 μm

In an embodiment, the invention provides an electrochemical cellcomprising:

-   -   a positive electrode;    -   a negative electrode;    -   a first membrane layer being positioned proximate to one of the        positive electrode and the negative electrode, the first        membrane layer comprising a support structure comprising a        plurality of apertures and a solid or gel electrolyte disposed        within the apertures of the support structures, wherein the        support structure formed of an electronically insulating        material or is formed of an electronically conducting material        at least partially coated with an electronically insulating        material;    -   a second membrane layer being positioned proximate to the other        of the positive and the negative electrode and proximate to the        first membrane layer, the second membrane layer comprising a        plurality of pores, the pores of the second membrane layer not        overlapping the apertures of the first membrane layer and the        pores comprising a liquid electrolyte;    -   wherein each of the first and second membrane layer is ionically        conductive and at least one of the first and second membrane        layers is electronically insulating.

In an additional embodiment, the invention provides an electrochemicalcell comprising:

-   -   a positive electrode;    -   a negative electrode;    -   a membrane layer being positioned proximate to an electrode, the        membrane layer comprising a support structure comprising a        plurality of apertures and a solid or gel electrolyte disposed        within the apertures of the support structures, wherein the        support structure is formed of an electronically insulating        material or is formed of an electronically conducting material        at least partially coated with an electronically insulating        material;        wherein the membrane layer is ionically conductive and at least        one side of the said membrane is electronically insulating.

In embodiments, the ionically conductive material or electrolyte is asingle material or a combination of materials. For example, in anembodiment, the ionically conductive material is a glass electrolyte ora ceramic electrolyte. A polymer electrolyte comprising a polymer host,a solvent and an alkali metal salt provides an example of anelectronically conductive material which can be viewed as a combinationof a materials. In a further embodiment, the ionically conductivematerial is a composite material such as a combination of particles orfibers of an ionically conductive material combined with anothermaterial such as a polymer, a carbonaceous material or a metallicmaterial.

In an embodiment, a solid electrolyte is selected from the groupconsisting of polymer electrolytes, glass electrolytes and ceramicelectrolytes. In an embodiment, the solid electrolyte is a oxide orsulfide glass electrolyte. In an embodiment, the oxide glass electrolyteis selected from LVSO and LIPON. In a further embodiment, theelectrolyte is a crystalline ceramic electrolyte. In an embodiment, thecrystalline ceramic electrolyte is a NASICON type electrolyte, a LISICONtype electrolyte or a perovskite electrolyte.

In an embodiment, the material(s) for the solid electrolyte orelectronically and ionically conductive material are selected from thegroup consisting of carbon, lithium titanate, Li₂O₂, Li₂O, titaniumdisulfide, iron phosphate, SiO₂, V₂O₅, lithium iron phosphate, MnO₂,A₁₂O₃, TiO₂, LiPF₆, Li₃P, Li₃N, LiNO₃, LiClO₄, LiOH, PEO, P₂O₅, LIPON,LISICON, ThioLISICO, Ionic Liquids, Al, Cu, Ti, Stainless Steel, Iron,Ni, graphene oxide, PEDOT-PSS, and combinations thereof.

In additional aspects of the invention methods for operatingelectrochemical cells are provided, the methods relating to any of theelectrochemical cells provided herein. In an embodiment, the inventionprovides a method of operating an electrochemical cell, the methodcomprising the steps of: providing said electrochemical cell asdescribed herein and charging, discharging or charging and dischargingthe electrochemical cell, thereby inducing a surface charge on thesurface of the electronically conductive layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. Schematic illustration of layer one of an exemplary membrane, afirst pattern of LISICON disks (dark gray) fills the holes in a metallicmatrix (light gray). Each solid electrolyte disk can be about 10 mm.After baking, at several hundreds of degrees Celsius, a polymer coatingis applied on the metallic part. The design of the first layer overcomesthe brittleness, large thickness and expensive cost of ceramic-basedsolid electrolytes.

FIG. 2. Schematic illustration of layer two of an exemplary membrane, asecond pattern of holes, each about 0.2 mm, is such that the holes ofthe second layer are aligned such that they have no overlap with thesolid electrolyte filled holes of the first layer, offset design. Thedesign of the second layer limits the size of the largest short, whichreduces the chance of a catastrophic failure. The offset property of thetwo-layer design enforces a unique tortuosity such that the appliedmechanical pressure may result in stopping the growth of dendrites bykinetic frustration.

FIG. 3. Schematic illustration of two layers A and B of an exemplarymembrane A) Placed next to the cathode layer: Layer one, metal framewith polymer coating (0.007 mm aluminum, stainless steel or copper and2×0.003 mm polyimide or polyester) with about 80% porosity filled withsolid electrolyte (LISICON). B) Placed next to the lithium layer: Layertwo, 0.010 mm thick aluminized polymer (polyimide or polyester) withabout 10% porosity filled with nonwoven or micro-porous separator andaqueous electrolyte. The two layers can be attached by a 0.002 mm porousPVDF, 80% opening.

FIG. 4. Schematic illustration of a cell with four types of element: 1)Anode (e.g. Li metal in Li-ion batteries or Zn—ZnO in Zinc batteries).2) Cathode (e.g. NMC, Sulfur, Air, LCO or LFP in Li-ion batteries orGraphite, NiOOH or Ag—AgO in Zinc batteries). 3) Separator layers, e.g.,microporous or nonwoven PE, PP, PVDF, polyester or polyimides. 4)Perforated or porous conductive layer, e.g., Ni, Ti, stainless steel, Cuor Al.

FIG. 5. Schematic illustration of another cell with four types ofelement 1) Anode (e.g. Li metal in Li-ion batteries of Zn—ZnO in Zincbatteries). 2) Cathode (e.g. NMC, Sulfur, Air, LCO or LFP in Li-ionbatteries or Graphite, NiOOH or Ag—AgO in Zinc batteries. 3) Separatorlayers, e.g. microporous or nonwoven PE, PP, PVDF, polyester orpolyimides. 4) Perforated or porous conductive layer, e.g., Ni, Ti,stainless steel, Cu or Al.

FIG. 6. Schematic illustration of a cell with five types of element 1)Anode (e.g. Li metal in Li-ion batteries of Zn—ZnO in Zinc batteries).2) Cathode (e.g. NMC, Sulfur, Air, LCO or LFP in Li-ion batteries orGraphite, NiOOH or Ag—Ago in Zinc batteries. 3) Separator layer(s), e.g.microporous or nonwoven PE, PP, PVDF, polyester or polyimides. 4)Perforated or porous conductive layer, e.g., Ni, Ti, stainless steel, Cuor Al. 5) Solid Electrolyte layer, e.g., LISICON.

FIG. 7. Schematic illustration of another a cell with five types ofelement 1) Anode (e.g. Li metal in Li-ion batteries of Zn—ZnO in Zincbatteries). 2) Cathode (e.g. NMC, Sulfur, Air, LCO or LFP in Li-ionbatteries or Graphite, NiOOH or Ag—Ago in Zinc batteries. 3) Separatorlayer(s), e.g. microporous or nonwoven PE, PP, PVDF, polyester orpolyimides. 4) Perforated or porous conductive layer, e.g., Ni, Ti,stainless steel, Cu or Al. 5) Solid Electrolyte layer in a frame, e.g.,LISICON in an aluminum-Polyester frame.

FIG. 8. Schematic illustration of an additional cell with five types ofelement 1) Anode (e.g. Li metal in Li-ion batteries of Zn—ZnO in Zincbatteries). 2) Cathode (e.g. NMC, Sulfur, Air, LCO or LFP in Li-ionbatteries or Graphite, NiOOH or Ag—Ago in Zinc batteries. 3) Separatorlayers, e.g. perforated PE, PP, PVDF, polyester or polyimides withpattern A. 4) Perforated or porous conductive layer, e.g., Ni, Ti,stainless steel, Cu or Al. 5) Solid Electrolyte layer in a frame withpattern B, e.g., LISICON in an aluminum-Polyester frame.

FIG. 9. Schematic illustration of a further cell with five types ofelement 1) Anode (e.g. Li metal in Li-ion batteries of Zn—ZnO in Zincbatteries). 2) Cathode (e.g. NMC, Sulfur, Air, LCO or LFP in Li-ionbatteries or Graphite, NiOOH or Ag—Ago in Zinc batteries. 3) Separatorlayers, e.g. perforated PE, PP, PVDF, polyester or polyimides withpattern A. 4) Perforated or porous conductive layer with pattern B,e.g., Ni, Ti, stainless steel, Cu or Al. 5) Solid Electrolyte layer in aframe, 4, with pattern B, e.g., LISICON in an aluminum-Polyester frame.

FIG. 10. Schematic illustration of another cell with five types ofelement 1) Anode (e.g. Li metal in Li-ion batteries of Zn—ZnO in Zincbatteries). 2) Cathode (e.g. NMC, Sulfur, Air, LCO or LFP in Li-ionbatteries or Graphite, NiOOH or Ag—Ago in Zinc batteries. 3) Separatorlayers, e.g. microporous or nonwoven PE, PP, PVDF, polyester orpolyimides. 4) Perforated or porous conductive layer, e.g., Ni, Ti,stainless steel, Cu or Al. 5) Solid Electrolyte layer in a frame, 4,e.g., LISICON in an aluminum-Polyester frame.

FIG. 11. Schematic illustration of an additional further cell with fivetypes of element 1) Anode (e.g. Li metal in Li-ion batteries of Zn—ZnOin Zinc batteries). 2) Cathode (e.g. NMC, Sulfur, Air, LCO or LFP inLi-ion batteries or Graphite, NiOOH or Ag—Ago in Zinc batteries. 3)Separator layers, e.g. microporous or nonwoven PE, PP, PVDF, polyesteror polyimides. 4) Perforated or porous conductive layer, e.g., Ni, Ti,stainless steel, Cu or Al. 5) Solid Electrolyte layer in a frame, 4;e.g., LISICON in an aluminum-Polyester frame.

FIG. 12: Coating weights of polymer electrolyte coated per unit area ofsubstrate, see Example 3.

FIGS. 13A and 13B: Scanning Electron Microscope (SEM) image of Kaptonsubstrate coated with PEO polymer. FIG. 13A: Top view. FIG. 13B: Crosssection.

FIGS. 13C, 13D and 13E: Additional SEM images of coated Kaptonsubstrates: FIG. 13C: Kapton+PEO, FIG. 13D: Kapton+PEO: LiClO₄/90:10.FIG. 13E: Kapton+PEO: LiClO₄/50:50.

FIGS. 13F, 13G and 13H show SEM images of coated Al substrates. FIG. 13Fshows an Al substrate coated with PEO, FIG. 13G shows Al+PEO:LiClO4/90:10, FIG. 13H shows Al+PEO: LiClO4/50:50.

FIG. 14A-14D: FIG. 14A: Kapton+PEO; FIG. 14B: Kapton+PEO: LiClO₄/90:10;FIG. 14C: Kapton+PEO: LiClO₄/70:30; FIG. 14D: Kapton+PEO: LiClO₄/50:50.

FIG. 14E-14H: FIG. 14E: Al+PEO; FIG. 14F: Al+PEO: LiClO₄/90:10; FIG.14G: Al+PEO: LiClO₄/70:30; FIG. 14H: Al+PEO: LiClO₄/50:50.

FIG. 15: Average open circuit voltage (OCV) measurements of the LCO halfcoin cells of Example 3.

FIG. 16: (a) and (b): illustrations of the measurement elements used.

FIGS. 17A-17C: Results obtained from circuit simulation of the Nyquistplot. Displays the summary of results obtained from relationship betweencoin cells with different polymer coated electrolyte and 17A: ohmicresistance, 17B: double-layer capacitance, and 17C: polarizationresistance.

FIG. 18: The overlaid Nyquist plots of the data shown in FIGS. 16A-16C.

FIG. 19: First cycle charge capacity, discharge capacity and percentretention of the coin cells with different polymer separator of Example3.

FIGS. 20A-20B: shows the cycle life of the cell in Example 3. Firstcycle with PEO:90:10 configuration coated on Kapton and Al mesh. FIG.20A. Charge cycle. FIG. 20B. Discharge cycle.

FIG. 21 Coating weights of PVDF based slurry coated separators inExample 4.

FIG. 22A-22F: Microscope images of substrates coated with PVDF baseslurries: FIG. 22A: Kapton® coated with PVDF and LTO slurry. FIG. 22B:Kapton coated with PVDF, LTO, and CF slurry. FIG. 22C: Kapton coatedwith PVDF, and graphite slurry. FIG. 22D: Al mesh coated with PVDF andLTO slurry. FIG. 22E: Al mesh coated with PVDF, LTO and CF slurry. FIG.22F: Al mesh coated with PVDF, and graphite slurry.

FIG. 23: SEM image of Al mesh coated with PVDF.

FIGS. 24A and 24B: SEM image of Al (FIG. 24A) mesh and Kapton (FIG. 24B)coated with PVDF and graphite slurry.

FIG. 25 Average open circuit voltage (OCV) measurements of the LCO halfcoin cells in Example 4.

FIGS. 26A-26C summarize the results obtained from circuit simulation ofthe Nyquist plot. Displayed is the summary of results in therelationship between coin cells with different polymer coatedelectrolyte and FIG. 26A: ohmic resistance, FIG. 26B: double-layercapacitance, and FIG. 26C: polarization resistance

FIG. 27 Nyquist plot corresponding to FIGS. 26A-26C.

FIG. 28: First cycle charge capacity, discharge capacity, and percentretention of the coin cells with Kapton and Al mesh coated with PVDF andgraphite slurry.

FIGS. 29A-29B: Cycle life of cells with Kapton and Al mesh substratecoated with PVDF and graphite slurry. FIG. 29A: charge cycle. FIG. 28B:discharge cycle.

DETAILED DESCRIPTION

In general the terms and phrases used herein have their art-recognizedmeaning, which can be found by reference to standard texts, journalreferences and contexts known to those skilled in the art. The followingdefinitions are provided to clarify their specific use in the context ofthe invention.

Referring to the drawings, like numerals indicate like elements and thesame number appearing in more than one drawing refers to the sameelement. In addition, hereinafter, the following definitions apply:

The term “electrochemical cell” refers to devices and/or devicecomponents that convert chemical energy into electrical energy orelectrical energy into chemical energy. Electrochemical cells have twoor more electrodes (e.g., positive and negative electrodes) and anelectrolyte, wherein electrode reactions occurring at the electrodesurfaces result in charge transfer processes. Electrochemical cellsinclude, but are not limited to, primary batteries, secondary batteriesand electrolysis systems. In certain embodiments, the termelectrochemical cell includes fuel cells, supercapacitors, capacitors,flow batteries, metal-air batteries and semi-solid batteries. Generalcell and/or battery construction is known in the art, see e.g., U.S.Pat. Nos. 6,489,055, 4,052,539, 6,306,540, Seel and Dahn J. Electrochem.Soc. 147(3) 892-898 (2000).

The term “capacity” is a characteristic of an electrochemical cell thatrefers to the total amount of electrical charge an electrochemical cell,such as a battery, is able to hold. Capacity is typically expressed inunits of ampere-hours. The term “specific capacity” refers to thecapacity output of an electrochemical cell, such as a battery, per unitweight. Specific capacity is typically expressed in units ofampere-hours kg⁻¹.

The term “discharge rate” refers to the current at which anelectrochemical cell is discharged. Discharge rate can be expressed inunits of ampere. Alternatively, discharge rate can be normalized to therated capacity of the electrochemical cell, and expressed as C/(X t),wherein C is the capacity of the electrochemical cell, X is a variableand t is a specified unit of time, as used herein, equal to 1 hour.

“Current density” refers to the current flowing per unit electrode area.

Electrode refers to an electrical conductor where ions and electrons areexchanged with electrolyte and an outer circuit. “Positive electrode”and “cathode” are used synonymously in the present description and referto the electrode having the higher electrode potential in anelectrochemical cell (i.e. higher than the negative electrode).“Negative electrode” and “anode” are used synonymously in the presentdescription and refer to the electrode having the lower electrodepotential in an electrochemical cell (i.e. lower than the positiveelectrode). Cathodic reduction refers to a gain of electron(s) of achemical species, and anodic oxidation refers to the loss of electron(s)of a chemical species. Positive electrodes and negative electrodes ofthe present electrochemical cell may further comprise a conductivediluent, such as acetylene black, carbon black, powdered graphite, coke,carbon fiber, graphene, and metallic powder, and/or may furthercomprises a binder, such as a polymer binder. Useful binders forpositive electrodes in some embodiments comprise a fluoropolymer such aspolyvinylidene fluoride (PVDF). Positive and negative electrodes of thepresent invention may be provided in a range of useful configurationsand form factors as known in the art of electrochemistry and batteryscience, including thin electrode designs, such as thin film electrodeconfigurations. Electrodes are manufactured as disclosed herein and asknown in the art, including as disclosed in, for example, U.S. Pat. Nos.4,052,539, 6,306,540, and 6,852,446. For some embodiments, the electrodeis typically fabricated by depositing a slurry of the electrodematerial, an electronically conductive inert material, the binder, and aliquid carrier on the electrode current collector, and then evaporatingthe carrier to leave a coherent mass in electrical contact with thecurrent collector.

“Electrode potential” refers to a voltage, usually measured against areference electrode, due to the presence within or in contact with theelectrode of chemical species at different oxidation (valence) states.

“Electrolyte” refers to an ionic conductor which can be in the solidstate, the liquid state (most common) or more rarely a gas (e.g.,plasma).

“Standard electrode potential”) (E°) refers to the electrode potentialwhen concentrations of solutes are 1M, the gas pressures are 1 atm andthe temperature is 25 degrees Celsius. As used herein standard electrodepotentials are measured relative to a standard hydrogen electrode.

“Active material” refers to the material in an electrode that takes partin electrochemical reactions which store and/or deliver energy in anelectrochemical cell.

“Cation” refers to a positively charged ion, and “anion” refers to anegatively charged ion.

“Electrical contact,” “electrical communication”, “electronic contact”and “electronic communication” refer to the arrangement of one or moreobjects such that an electric current efficiently flows from one objectto another. For example, in some embodiments, two objects having anelectrical resistance between them less than 100Ω are considered inelectrical communication with one another. An electrical contact canalso refer to a component of a device or object used for establishingelectrical communication with external devices or circuits, for examplean electrical interconnection. “Electrical communication” also refers tothe ability of two or more materials and/or structures that are capableof transferring charge between them, such as in the form of the transferof electrons. In some embodiments, components in electricalcommunication are in direct electrical communication wherein anelectronic signal or charge carrier is directly transferred from onecomponent to another. In some embodiments, components in electricalcommunication are in indirect electrical communication wherein anelectronic signal or charge carrier is indirectly transferred from onecomponent to another via one or more intermediate structures, such ascircuit elements, separating the components.

“Electrical conductivity” or “electrically conductive” refers totransfer of charges which can be ionic (ions) or electronic (electrons).“Electronic conductivity” or “electronically conductive” refers totransfer of charges which are electronic (electrons). “Ionicconductivity” or “ionically conductive” refers to transport of ioniccharge carriers.

“Thermal contact” and “thermal communication” are used synonymously andrefer to an orientation or position of elements or materials, such as acurrent collector or heat transfer rod and a heat sink or a heat source,such that there is more efficient transfer of heat between the twoelements than if they were thermally isolated or thermally insulated.Elements or materials may be considered in thermal communication orcontact if heat is transported between them more quickly than if theywere thermally isolated or thermally insulated. Two elements in thermalcommunication or contact may reach thermal equilibrium or thermal steadystate and in some embodiments may be considered to be constantly atthermal equilibrium or thermal steady state with one another. In someembodiments, elements in thermal communication with one another areseparated from each other by a thermally conductive material orintermediate thermally conductive material or device component. In someembodiments, elements in thermal communication with one another areseparated by a distance of 1 μm or less. In some embodiments, elementsin thermal communication with one another are provided in physicalcontact.

“Chemically resistant” refers a property of components, such as layers,of separators and electrochemical systems of the invention wherein thereis no significant chemical or electrochemical reactions with the cellactive materials, such as electrodes and electrolytes. In certainembodiments, chemically resistant also refers to a property wherein thetensile retention and elongation retention is at least 90% in theworking environment of an electrochemical system, such as anelectrochemical cell.

“Thermally stable” refers a property of components, such as layers, ofseparators and electrochemical systems of the invention wherein there isno significant chemical or electrochemical reactions due to normal andoperational thermal behavior of the cell. In certain embodiments,thermally stable also refers to materials wherein the melting point ismore than 100 Celsius, and preferably for some embodiments more than 300Celsius, and optionally the coefficient of thermal expansion is lessthan 50 ppm/Celsius. In an embodiment, thermally stable refers to aproperty of a component of the separator system such that it may performin a rechargeable electrochemical cell without undergoing a change sizeor shape with the temperature that significantly degrades theperformance of the electrochemical cell.

“Porosity” refers to the amount of a material or component thatcorresponds to pores, such as apertures, channels, voids, etc. Porositymay be expressed as the percentage of the volume of a material,structure or device component, such as a high mechanical strength layer,that corresponds to pores, such as apertures, channels, voids, etc.,relative to the total volume occupied by the material, structure ordevice component.

High mechanical strength” refers to a property of components ofseparator systems of the invention, such as first, second, third andfourth high mechanical strength layers, having a mechanical strengthsufficient to prevent physical contact of opposite electrodes,sufficient to prevent short circuiting due to external objects withinthe cell, such as metallic particles from fabrication, and sufficient toprevent short circuiting due to growth of dendrites between positive andnegative electrodes of an electrochemical cell, for example, duringcharge and discharge cycles of a secondary electrochemical cell. In anembodiment, for example, a high mechanical strength layer has amechanical strength sufficient to prevent piercing due to externalobjects in the cell, such as metallic particles from the fabrication,and shorts due to the growth of dendrites between electrodes. In anembodiment, for example, a high mechanical strength layer has amechanical strength sufficient to prevent shorting between the positiveelectrode and the negative electrode of an electrochemical cell due toexternal objects in the cell such as metallic particles from thefabrication and shorts due to the growth of dendrites betweenelectrodes. In an embodiment, for example, a high mechanical strengthlayer is characterized by a Young's modulus greater than or equal to 500MPa, and optionally for some applications a Young's modulus greater thanor equal to 1 GPa, and optionally for some applications a Young'smodulus greater than or equal to 10 GPa, and optionally for someapplications a Young's modulus greater than or equal to 100 GPa. In anembodiment, for example, a high mechanical strength layer ischaracterized by a yield strength greater than or equal to 5 MPa, andoptionally for some applications a yield strength greater than or equalto 50 MPa, and optionally for some applications a yield strength greaterthan or equal to 100 MPa, and optionally for some applications a yieldstrength greater than or equal to 500 MPa. In an embodiment, forexample, a high mechanical strength layer is characterized by apropagating tear strength greater than or equal to 0.005 N, andoptionally for some applications a propagating tear strength greaterthan or equal to 0.05 N, a propagating tear strength greater than orequal to 0.5 N, a propagating tear strength greater than or equal to 1N. In an embodiment, for example, a high mechanical strength layer ischaracterized by an initiating tear strength greater than or equal to 10N, and optionally for some applications an initiating tear strengthgreater than or equal to 100 N. In an embodiment, for example, a highmechanical strength layer is characterized by a tensile strength greaterthan or equal to 50 MPa, and optionally for some applications a tensilestrength greater than or equal to 100 MPa, and optionally for someapplications a tensile strength greater than or equal to 500 MPa, andoptionally for some applications a tensile strength greater than orequal to 1 GPa. In an embodiment, for example, a high mechanicalstrength layer is characterized by an impact strength greater than orequal to 10 N cm, and optionally for some applications to an impactstrength greater than or equal to 50 N cm, and optionally for someapplications to an impact strength greater than or equal to 100 N cm,and optionally for some applications to an impact strength greater thanor equal to 500 N cm.

Electrochemical Cell.

In an embodiment, the electrochemical cell is a secondary (rechargeable)electrochemical cell. In another embodiment, the electrochemical cell isa primary electrochemical cell. In embodiments, the electrochemical cellis a primary battery, a secondary battery, a fuel cell or a flowbattery, a lithium battery, a lithium ion battery, a zinc anode-basedbattery, a nickel cathode-based battery, a semi-solid battery or alead-acid-based battery. In additional embodiments, the electrochemicalcell is a Li—S, Li-Air, Li—LiFePO₄, or Zn—Ni electrochemical cell. Infurther embodiments the cell is Mg based or Na based.

Negative Electrode

In an embodiment where the cell is a lithium ion cell, the activematerial of the negative electrode is lithium metal, a lithium alloy,silicon, a silicon alloy, silicon-graphite or graphite. In a furtherembodiment, active materials suitable for use in the negative electrodeof a lithium-ion cell include, but are not limited to carbonaceousmaterial, lithium titanate (LTO) and titanium dioxide (TiO₂).Carbonaceous materials include, but are not limited to natural graphite,highly ordered pyrolytic graphite (HOPG), Meso Carbon Microbeads (MCMB)and carbon fiber.

In an embodiment where the cell is a zinc cell, the anode material is Znmetal, ZnO or Zn—ZnO. In an embodiment, the negative electrode comprisesan active material in electronic communication with a current collector.In an embodiment, the current collector comprises an external connectiontab; in an embodiment the external connection tab is integral with thecurrent collector. In an embodiment, the current collector is anelectronically conductive material such as a metal.

Positive Electrode

In embodiments where the cell is a lithium ion cell, the active materialof the positive electrode is NMC (lithium nickel-manganese-cobaltoxide), sulfur, sulfur-carbon, carbon-air, LCO (lithium cobalt oxide,LiCoO₂) or LFP (lithium iron phosphate, LiFePO₄). In a furtherembodiment, active materials suitable for use in the positive electrodeof a lithium-ion cell include, but are not limited to Lithium Cobalt(LiCoO₂), Lithium Manganese Oxide (LiMn₂O₄), Lithium Iron Phosphate(LiFePO₄), Lithium Nickel Cobalt Aluminum Oxide(LiNi_(0.8)CO_(0.15)Al_(0.05)O₂) and Lithium Nickel manganese CobaltOxide (LiNi_(0.33)Mn_(0.33)Co_(0.33) O₂). Alternate materials includetitanium disulfide (TiS₂).

In embodiments where the cell is a zinc battery, the cathode material isgraphite, NiOOH, Ag, or AgO. In an embodiment, the positive electrodecomprises an active material in electronic communication with a currentcollector. In an embodiment, the current collector comprises an externalconnection tab; in an embodiment the external connection tab is integralwith the current collector. In an embodiment, the current collector isan electronically conductive material such as a metal.

In embodiment, the positive electrode may be an oxygen electrode or anair electrode. During discharge of the cell, hydroxide ions aregenerated through dissociation of oxygen and water at the surface of theoxygen or air electrode. During recharging of the cell, waterdissociates to hydroxide and oxygen at the air or oxygen electrode. U.S.Pat. No. 6,221,523 is hereby incorporated by reference for itsdescription of oxygen and air electrodes and catalyst depositionmethods.

Catalysts suitable for use with the positive electrode include metals,metal alloys, metal oxides and metal complexes. In an embodiment, asingle catalyst is suitable for both reduction of oxygen (duringdischarge) and evolution of oxygen (during charging). Such a catalystmay be termed a bifunctional catalyst. Bifunctional catalysts known tothe art include noble metal thin films, perovskites, and a spineloxides. Perovskite-type oxides include transition metal oxidesrepresented by the general composition formula ABO₃. One class ofperovskite-type oxide is LaCoO₃, partial substitution products in whichLa is partially substituted by one or more of Ca, Sr or Ba, partialsubstitution products in which Co is partially substituted by one ormore Mn, Ni, Cu, Fe, Ir, and substitution products in which both La andCo are partially substituted.

Electrolyte

In embodiments, the electrolyte is a liquid electrolyte, gelelectrolyte, polymer electrolyte or ceramic electrolyte. In embodiments,the electrolyte is aqueous or nonaqueous. When the electrochemical cellis a lithium ion battery, the electrolyte is preferably nonaqueous. Inan embodiment, the electrolyte comprises one or more lithium saltsdissolved in a nonaqueous solvent.

Solid Electrolyte

In an embodiment, the solid electrolyte can be a free standing layer ora coating layer. In another embodiment, the solid electrolyte is in theform of particles or fibers filling the holes-pores of an electronicallyinsulating layer or the electronically conductive layer. In anembodiment, a layer is provided comprising at least a porous layer ofelectronically conductive material and at least a group of fibers orparticles filling the pores or holes of the porous layer. A variety ofsolid electrolytes are known to the art and include, but are not limitedto LISICON (Lithium super ionic conductor, Li_(2+2x)Zn_(1−x)GeO₄), PEO(polyethylene oxide), NASICON, and LIPON.

Optionally, the first ionically conductive and electronically insulatingmaterial comprises a solid electrolyte, a gel electrolyte, a polymerelectrolyte, LISICON, NASICON, PEO, Li₁₀GeP₂S₁₂, LIPON, PVDF, Li₃N,Li₃P, LiI, LiBr, LiCl, LiF, oxide perovskite, La_(0.5), Li_(0.5)TiO₃,thio-LISICON, Li_(3.25)Ge_(0.25)P_(0.75)S₄, glass ceramics, Li₇P₃S₁₁,glassy materials, Li₂S—SiS₂—Li₃PO₄, lithium nitride, polyethylene oxide,Doped Li₃N, Li₂S—SiS₂—Li₃PO₄, LIPON, Li₁₄Zn(GeO₄)₄, Li-beta-alumina,Li_(3.6)Si_(0.6)P_(0.4)O₄, Li₂S—P₂S₅, PEO-LiClO₄,LiN(CF₃SO₂)₂/(CH₂CH₂O)₈, NaPON, ZrO₂, Nafion, PEDOT:PSS, SiO₂, PVC,glass fiber mat, alumina, silica glass, ceramics, glass-ceramics,water-stable polymers, glassy metal ion conductors, amorphous metal ionconductors, ceramic active metal ion conductors, glass-ceramic activemetal ion conductors, an ion conducting ceramic, an ion conducting solidsolution, an ion conducting glass, a solid lithium ion conductor or anycombination of these.

In an embodiment, the solid electrolyte is a polymer electrolyte. In anembodiment, polymer electrolyte is a polyelectrolyte comprising ionicgroups. In an embodiment, the polyelectrolyte is an ionomer. In anembodiment, an ionomer is a copolymer comprising nonionic repeat unitsand ion containing repeat units. In an embodiment, the ionic groupslocated upon nonpolar backbone chains. In an embodiment, the amount ofionic groups is 1 mol % to 15 mol %. In an embodiment, the polymerelectrolyte comprises a polymer complexed with an alkali metal salt.Polymer electrolytes known to the art include, but are not limited to,poly(ethylene) oxide (PEO), poly(acrylonitrile) (PAN), poly(methylmethacrylate) (PMMA); poly(vinylidene fluoride) (PVdF) andpoly(vinylidene fluoride-hexafluoro propylene) (PVdF-HFP) Lithium saltsused in for forming complexes include LiBr, LiI, LiCl, LiSCN, LiClO₄,LiCF₃SO₃, LiBF₄ and LiAsF₆.

In an embodiment, the solid electrolyte is a gelled or wet polymer. Thegelled polymer may further comprise an organic liquid solvent and analkali metal salt. The polymer host may comprise poly(ethylene) oxide(PEO), poly(acrylonitrile) (PAN), poly(methyl methacrylate) (PMMA),poly(vinylidene fluoride) (PVdF) and poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP). Solvents include, but are not limited to ethylenecarbonate, propylene carbonate, dimethyl formamide, diethyl phthalate,diethyl carbonate, methyletyl carbonate, dimethyl carbonate,γ-butyrolactone, glycol sulfite and alkyl phthalates.

In a further embodiment, the solid-state ionically conductive materialis supported by a frame or porous support. In an embodiment, the frameor support is made of an electronically insulating material or of anelectronically conducting material surface coated with an electronicallyinsulating material. In an embodiment, the support is porous orperforated and the holes or pores at least partially filled by particlesor fibers of the solid-state ionically conductive material. Suitableactive materials include, but are not limited to, traditional electrodeactive materials such as LiTiO₂, silicon or graphite. In an embodiment,application of a voltage or current between the electronicallyconducting layer and one of the electrodes results in gain and releaseof ions by the fibers or particles, such that ionic charge carriers areable to be transported between said positive electrode and said negativeelectrode through the pores or holes of the electronically conductinglayer. For example, a pulse or sinusoidal voltage between 1 and 2.5 Vmay be applied between a graphite anode and a layer comprising LiTiO2fibers inside a copper matrix in a Li-ion cell with a cathode such asair or sulfur.

In an embodiment, the solid-state ionically conducting material isprovided in the form of pellets inserted in the frame such as a metallicframe. In an embodiment, the pellets are bonded to the frame throughsolid state methods. In a further embodiment, binders (such as polymericbinders) and/or cements such as (silica, alumina or iron oxide).Additional surface coatings may be applied to overcome interfacialresistance between the supported solid-state ionically conductingmaterial and the electrode.

In another embodiment, the solid-state ionically conductive material isprovided as a composite of particles of the ionically conductivematerial with binder. As examples, the amount of binder is from 5% to35%, 5%-25%, 5%-20%, 5%-15% or 5%-10% (wt %). In a further embodiment,electronically conductive particles may be included in the composite. Asan example, the amount of electronically conductive particles is from 5wt % to 10 wt %. In an additional embodiment, particles of anelectronically insulating material such as alumina are included in thecomposite. For example, the amount of alumina is from 5 wt % to 15 wt %.The composite material may form a porous layer; in embodiments theamount of porosity is from 20-60-% or from 40-60% (vol %). Thesolid-state ionically conductive material may comprise an conventionalsolid electrolyte, an electrochemically active ion-conductive materialor a combination thereof. In an embodiment, the amount ofelectrochemically active ion-conductive material in this mixture is from5% to 20% or 5% to 10% (wt %).

Insulator

In embodiments, the electronically insulating layer comprises a polymer,an oxide, a glass or a combination of these. In embodiments, theelectronically insulating is nonwoven or a woven. In an embodiment, theinsulating layer is polymeric such as microporous or nonwoven PE, PP,PVDF, polyester or polyimide. In a further embodiment the insulatinglayer is an oxide such as aluminum oxide. In an embodiment, saidelectronically insulating comprises a coating provided on at least oneside of said electronically conductive layer. As an example, an aluminumoxide layer is provided on an aluminum layer. In an embodiment, theelectronically insulating comprises one or more perforated or porouslayers each independently having a porosity greater than or equal to30%, from 30% to 80% or from 50% to 75%. In an embodiment, one or moreperforated or porous layers each independently have a thickness selectedover the range of 20 nm to 1 mm, 0.005 mm to 1 mm, from 1 μm to 500 μmor from 5 μm to 100 μm. In an embodiment, the separator comprises afirst insulating layer having a plurality of apertures arranged in afirst pattern and a second insulating layer having a plurality ofapertures arranged in a second pattern; wherein said second pattern hasan off-set alignment relative to said first pattern such that an overlapof said apertures of said first insulating layer and said apertures ofsaid second insulating layer along axes extending perpendicularly fromsaid first insulating layer to said second insulating layer is less thanor equal to 20% In an embodiment, there is no overlap of the apertures.

Ionically Conductive Layer

In an embodiment, for example, a layer permeable to ionic chargecarriers has an ionic resistance less than or equal to 20 ohm-cm², andpreferably for some embodiments less than or equal to 2 ohm-cm², andpreferably for some embodiments less than or equal to 1 ohm-cm².

In an embodiment, the electronically and ionically conducting materialor a material to be included in an a combination to produce anelectronically and ionically conducting material mixture is selectedfrom the group consisting of carbon, lithium titanate, Li₂O₂, Li₂O,titanium disulfide, iron phosphate, SiO₂, V₂O₅, lithium iron phosphate,MnO₂, Al₂O₃, TiO₂, LiPF₆, Li₃P, Li₃N, LiNO₃, LiClO₄, LiF, LiOH,poly(ethylene oxide) (PEO), P₂O₅, LIPON, LISICON, ThioLISICO, an ionicliquid, Al, Cu, Ti, Stainless Steel, Iron, Ni,Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT-PSS),graphene oxide and combinations thereof. In a further embodiment, anelectrolyte material or a material to be included in a combination toproduce an electrolyte wherein the materials for the said electronicallyand ionically conductive material are selected from the group consistingof carbon, lithium titanate, Li₂O₂, Li2O, titanium disulfide, ironphosphate, SiO₂, V₂O₅, lithium iron phosphate, MnO₂, Al₂O₃, TiO₂, LiPF₆,Li₃P, Li₃N, LiNO₃, LiClO₄, LiOH, PEO, P₂O₅, LIPON, LISICON, ThioLISICO,an ionic liquids, Al, Cu, Ti, Stainless Steel, Iron, Ni, graphene oxide,PEDOT-PSS, and combinations thereof.

Optionally, an ionically conductive and electronically insulatingmaterial has an ionic conductivity greater than or equal to 10⁻⁵ S/cm,greater than or equal to 10⁻⁴ S/cm, greater than or equal to 10⁻⁴ S/cm,greater than or equal to 10⁻³ S/cm, greater than or equal to 10⁻² S/cm,greater than or equal to 10⁻¹ S/cm, greater than or equal to 10 S/cm,selected from the range of 10⁻⁷ S/cm to 100 S/cm, selected from therange of 10⁻⁵ S/cm to 10 S/cm, selected from the range of 10⁻³ S/cm to 1S/cm. Optionally, the first ionically conductive and electronicallyinsulating material has an ionic conductivity selected from the range of10⁻⁷ S/cm to 100 S/cm at an operating temperature of the cell.

Optionally, the above-mentioned first ionically conductive andelectronically insulating material has an average porosity less than 1%.Preferably, the first ionically conductive and electronically insulatingmaterial is non-porous. Optionally, the first ionically conductive andelectronically insulating material has an average porosity selected fromthe range of 0% to 5%. Optionally, the first ionically conductive andelectronically insulating material is substantially free of pinholes,cracks, holes or any combination of these. Optionally, the firstionically conductive and electronically insulating material issubstantially free of defects. Optionally, the first ionicallyconductive and electronically insulating material is doped.

In an embodiment, the electronically insulating layers and theelectronically conducting layers each independently have an averagethickness selected over the range 25 nm to 1 mm, optionally for someapplications selected over the range 25 nm to 15 μm, and optionally forsome applications selected over the range of 1 μm to 100 μm, andoptionally for some applications selected over the range of 5 μm to 1mm. In an embodiment, for example, any of, and optionally all of,electronically insulating layers and the electronically conductinglayers each independently have an average thickness selected over therange 10 nm to 2 μm or selected over the range 2 μm to 50 μm.

Electronically Conductive Layer

In embodiments, said electronically conductive layer comprises achemically resistant material, a heat resistant material, a mechanicallyresistant material or any combination of these. In an embodiment, theconductive layer comprises a metal, alloy, carbon or a conductivepolymer. In an embodiment, the electronically conductive layer comprisesa metal foil, a metallic thin film, an electronically conductivepolymer, a carbonaceous material or a composite material of any ofthese. In an embodiment, the metal or alloy is selected from Al, Cu, Ti,Ni, Fe, stainless steel, Sn, Si, Au, Pt, Ag, Mn, Pb and their alloys andZircalloy, Hastalloy, and superalloys. In an embodiment, theelectronically conductive layer comprises a metal selected from thegroup consisting of Al, Ti, Cu, stainless steel, Ni, Fe, or any alloysor composites thereof. In an embodiment, the carbonaceous material isselected from conductive carbon, super-P, carbon black and activatedcarbon. In an embodiment, the electronically conducting polymer isselected from the linear-backbone “polymer blacks” (polyacetylene,polypyrrole, and polyaniline) and their copolymers, poly(p-phenylenevinylene) (PPV) and its soluble derivatives and poly(3-alkylthiophenes.In an embodiment, the electronically conducting layer does not reactchemically or electrochemically with the electrolyte. In an embodiment,electronically conductive layer comprises a metal reactive with anactive material of the negative or positive electrode. In an embodiment,the electronically conductive layer comprises a metal selected from thegroup consisting of Al and Sn. In embodiments, the thickness of theelectronically conductive layer is greater than zero and less than 1 mm,greater than zero and less than 0.1 mm, from 0.001 mm to 1 mm, from0.005 mm to 1 mm, from 0.005 mm to 0.5 mm, from 0.01 mm to 0.1 mm, from0.075 mm to 0.2 mm or from of 25 nm to 0.5 mm. In an embodiment, thecomposite separator further comprises one or more additionalelectronically conductive layers.

Fabrication of composite membranes may include bonding of differentmembrane layers. In an embodiment, a polymeric binder is used.

The invention may be further understood by the following non-limitingexamples.

Example 1: Novel Membranes

1) “A Unique Hybrid Membrane for Protecting Lithium Metal Anode or zincanode”

An exemplary hybrid membrane is a novel composite electrolyte composedof liquid, polymer and ceramic electrolytes, designed in a specialformat. The hybrid membrane has high conductivity (more than 1 mS/cm),mechanical strength (shear modulus=2 GPa; tensile strength=200 MPa;rupture strength=1000 gr) and flexibility. The membrane is low cost($1/sq. m) and can easily be produced in large quantities (rolls of 100m long, 6 cm width and 0.025 mm thickness). Using non-aqueouselectrolyte near the anode and aqueous electrolyte near the cathodeallows using high capacity air and sulfur cathodes with lithium metalanode. The membrane is chemically inert, does not react with lithiummetal, electrolytes, air or moisture, and separates the anolyte andcatholyte environments. A schematic figure and the mechanism of theperformance of the hybrid membrane are shown in FIGS. 1-2. The hybriddesign resolves the high cost, fragility and high resistivity of solidelectrolytes without compensating the safety. Lithium electroplating,including dendrite growth, is further controlled by a) providing highmechanical pressure on the surface of the lithium metal, b) manipulatingthe electric field by using a conductive layer inside the membrane. Itis expected that the novel hybrid electrolyte in conjunction with usingstate of the art electrolyte and additives can enable the nextgeneration of high energy batteries with double the energy at half thecost.

Placed next to the cathode layer: Layer one, metal frame with polymercoating (0.007 mm aluminum, stainless steel or copper and 2×0.003 mmpolyimide or polyester) with about 80% porosity filled with solidelectrolyte (e.g., LISICON). A first pattern of LISICON disks fills theholes in a metallic matrix. Each solid electrolyte disk can be about 10mm. After baking, at several hundreds of degrees Celsius, a polymercoating is applied on the metallic part. The design of the first layerovercomes the brittleness, large thickness and expensive cost ofceramic-based solid electrolytes, such as Ohara's.

Placed next to the lithium layer: Layer two, 0.010 mm thick aluminizedpolymer (polyimide or polyester) with about 10% porosity filled withnonwoven or micro-porous separator and aqueous electrolyte. A secondpattern of holes, each about 0.2 mm, is such that the holes of thesecond layer are aligned such that they have no overlap with the solidelectrolyte filled holes of the first layer, Offset design.

The design of the first layer overcomes the brittleness, large thicknessand expensive cost of ceramic-based solid electrolytes, such as Ohara's.The design of the second layer limits the size of the largest short,which reduces the chance of a catastrophic failure.

The offset property of the two-layer design enforces a unique tortuositysuch that the applied mechanical pressure may result in stopping thegrowth of dendrites by kinetic frustration.

A key element of our unique innovation is a double layer perforatedpolymer film designing the tortuosity of the separator the way acomposite material is made. Based on the concept of “offset” widely usedin the science of optics, we place two identical perforated layers in acomplementary pattern that prevents any light from passing from a sideto the other side of the layers without going through at least one ofthe layers. Further, to provide low resistivity required for high powerapplications, layers of high mechanical strength and layers of low ionicresistance are placed next to each other as a layered composite. Ourunique method allows fabrication of mechanically-thermally strongseparators from almost any materials, such as PEEK, Kapton, Polyesters,PET, polysulfone or even ceramics.

Protecting lithium metal anode is a critical step in developing andimproving the next generation of energy storage technologies, since theyrepresent the most critical component needed to enable widespreadcommercialization of PEVs. In this example, we are suggesting a uniquehybrid membrane for protecting lithium metal anode in advanced highenergy batteries, such as in lithium-sulfur and lithium-air batteries.The proposed membrane is a unique hybrid membrane with excellentconductivity, stability and flexibility that is needed for enablinglithium metal battery cells, with up to 500 Wh/Kg, 1000 Wh/L and 1000cycles. Our effort is focused on a unique class of advanced membraneswith non-expensive, efficient and scalable manufacturing.

To overcome the challenges of dendrite formation and lithiumcontamination during recharging lithium metal anode several interestingapproaches have been suggested. Several research groups, such as Balsaraat LBNL have been working on polymer based electrolytes with the goal ofstopping the dendrite formation or growth. Many different electrolytes(Doron Aurbach and Jeff Dahn pioneering work in 90's) and additives,such as LiNO₃, have been tested to control the reactions between lithiummetal and the electrolyte. Finally, PolyPlus has been using LISICONsolid electrolyte to prevent the contamination of lithium metal inlithium sulfur and lithium air cells. However, these efforts have notbeen sufficient yet. Polymer electrolytes with high mechanical strengthhave low conductivity and adhesiveness at room temperature. Additivesand different electrolytes have not been successful beyond anycoincells, as they still need the mechanical pressure on the lithiumsulfur. Ceramic electrolytes are still too thick, expensive and rigid.Thus, still there is a critical need for more advanced membranes thatcan help in protecting the lithium surface in advanced lithium metalbattery cells, larger than a few mAh.

TABLE 1 Membrane Protecting type Conductivity Cost DeformabilityScability lithium Aqueous Good Low High Excellent No electrolyte withseparator Polymer Poor Low Average Good No Electrolyte Ceramic Good VeryVery Poor Very Yes Electrolyte High poor Hybrid Good Low High Good YesMembrane (this work)

C-Layer Frame Fabrication Development

The frame of the C layer holds the ceramic electrolyte (e.g., LISICON)pellets in place during the manufacturing and operation. Metallic frameswill be used to overcome the high temperature (more than 500° C.) andmilling needed to process the ceramic electrolyte. At the end of theprocess, a thin electronically insulating layer will be coated on themetallic part. Thermal deformation of the metallic frame can overcomethe challenge of adherence of the pellets to the metallic frame. As anexample, nickel, aluminum and stainless steel can be used.

C-Layer Pellets Fabrication Development

We can use the guidelines and methods from recent literature on ceramicelectrolyte research to fabricate the ceramic pellets. The process isvery challenging and the dimensions of the pellets and processconditions play important roles in the quality of the product. We try toavoid the pinhole formation and cracks by optimizing the size of thepellets and the metallic frame structure.

Composite C-Layer Fabrication Development

Bonding the metallic frame to the ceramic pellets can be challenging.Solid state methods will be used as the first bonding method, such as a)Powder blending and consolidation (powder metallurgy): Powdered metaland discontinuous reinforcement are mixed and then bonded through aprocess of compaction, degassing, and thermo-mechanical treatment(possibly via hot isostatic pressing (HIP) or extrusion), and b) Foildiffusion bonding: Layers of metal foil are sandwiched with long fibers,and then pressed through to form a matrix.

Insulating polymer coating (a few micrometers) will be performed on themetallic frame as the final step.

In case the bonding between the metallic frame and the ceramic pelletsgets lose during fabrication or operation and thermal treating(difference in thermal coefficient of metals and ceramics) beinginsufficient, we will use binders such as PVDF polymer in NMP and cement(SiO2, Al2O3, Fe2O3 and CaO) in water. This process has similaritieswith making reinforced concrete in structural engineering. As we willuse non-aqueous with the cathodes in this testing, the interfacialresistance between the cathode and the C-layer may be high. Surfacetreatment such as PVDF and SiO2 coating can be used to overcome theproblem.

A-Layer Fabrication

Metalized polymer films will be perforated in a periodic format, 0.1 mmdiameter holes, by laser cutting, lithography or micro punching and theleast expensive method will be implemented. Handling 200 cm long of 0.01mm films can be challenging, especially if the film wrinkles, which cancause the perforation challenging. Especial engineering instruments willbe designed to address this challenge.

The objective is to measure the effect of A-layer on the performance oflithium metal anode cells. Especially the effectiveness of controllinglithium electroplating by a) designed tortuosity b) manipulating theelectrical field, due to the embedded conductive core layer will beinvestigated

Two of our suggested mechanisms to control the lithium metal dendriteforming and growth are a) Manipulating the electric field inside thecell by using an inner metallic layer in the membrane that generatessurface charges on its surface due to the charges on the lithium anodefilm. b) Applying mechanical pressure on most of the lithium metalsurface which has been proven to enhance the electroplating of lithium.The surface of the perforated polymer may be treated, for example byPVDF and SiO2 coating, such that the interface resistance between thelithium anode and the membrane be minimized.

Hybrid Membrane Fabrication Development

Fabrication of the final product, hybrid membrane, requires the bondingbetween the A-layer and C-layer. The bonding should be very rigid sothat we can implement our “designed tortuosity” mechanism to stop thegrowth of lithium dendrite. Attention will be given to the bondingbetween the C-layer and A-layer and also minimizing the bulk andinterfacial resistance of the membrane. The bonding should prevent anydirect contact between the ceramic pellets and lithium, as most highconductivity ceramic electrolytes react with lithium metal. As anexample, we can use PVDF and SiO2 (e.g., dissolved in acetone at 40° C.)as the binder between the layers, which will allow enough wetting of theC-layer by the anolyte and preserves the “offset” between the layers.

The design used the “designed tortuosity” in blocking the dendrite andimproving the electroplating of lithium.

The perfect separation between lithium metal-anolyte from thecathode-catholyte is essential in some cells. Impermeable polymerhousing for the cathode-catholyte can be used such that only the hybridmembrane remains uncovered. We may need to inject the catholyte by asyringe and then close the hole by heat sealing

Compressible Seal Development

The objective of this element is to implement a compressible seal thatcan ensure enough compressive pressure on the lithium surface even in afully discharged cell. Smooth electroplating of lithium ions requiresapplying enough pressure on the lithium anode surface. As the highspecific energy design limits us to spring-less formats, we use acompressible housing for lithium anode.

2) A novel flexible and inexpensive composite polymer-solid electrolyteelectrolyte that has very high ionic conductivity (ceramic powders, suchas TiO2 or lithium titanate bounded by polymers (about 10% weight) suchas pvdf or Polyethylene oxide). it allows making Li-air and Li—Sbatteries with energy densities 2-4× higher than state of the art.Traditional methods make ceramic electrolytes without any binders, hencethere are limitations on the size of the film; it has to be thick toavoid pinholes but this makes the, brittle. Also the dimensions (surfacearea) are limited to about 10 cm×10 cm. In our novel method, we can makeceramic-polymer electrolytes as thin as 20 micrometers and with highsurface area, such as 2 m×6 cm. further, our solid electrolyte isflexible and can be used in traditional batteries such as 18650manufacturing.

3) Spar (e.g. two perforated layers having a misfit between alignment ofapertures) with different openings on each side: 20% on the Li and 80%on the Cathode. LTO, Li₂O₂, Titanium disulfide, FePO₄ and solidelectrolytes deposited on nonwoven separator or in the holes of Spar.

4) Coating the surface of the “electrolyte/separator with filled holes”particles with a hydrophobic skin, e.g., polydopamine, allows Li⁺transport while stabilizing the electrolyte particles in an aqueouselectrolyte.

5) The stable surfaces of Li₂O₂ are half-metallic, despite the fact thatLi₂O₂ is a bulk insulator. A composite polymer gel containing a largevolume fraction of an inorganic oxide and an organic liquid electrolyteimmobilized in a polymer can give a flexible, thin membrane with aσ_(Li)≈10⁻³ S cm⁻¹, may assist in blocking dendrites from a Li anode orsoluble redox couples in a liquid cathode. In contrast, the stablesurfaces of Li₂O are insulating and nonmagnetic. The distinct surfaceproperties of these compounds may explain observations ofelectrochemical reversibility for systems in which Li₂O₂ is thedischarge product and the irreversibility of systems that discharge toLi₂O. Moreover, the presence of conductive surface pathways in Li₂O₂could offset capacity limitations expected to arise from limitedelectron transport through the bulk solid electrolyte such as LTO,Li₂O₂, TiS₂, FePO₄, or for Fuel cells, where the inside the electrolyteis electronically conductive (such as Al or Ni or Tin layer in themiddle) but it is electronically disconnected from the electrodes.Aluminized Mylar show how one can make it. In fact in fuel cells andNa—S batteries or Molten salt batteries or molten batteries they usehigh temperature, here I suggest using electronic conductivity+cellelectric field (my experiments: middle of the cell is ½ of the totalvoltage!)

6) Coating on separator or filing the holes in Spar amphiphilicpolymers—polymers composed of hydrophilic (water-loving) and hydrophobic(water-hating) parts—in modifying the interface between sulfur and thehollow carbon nanofiber, they used polyvinylpyrrolidone (PVP). AlsoLithium stearate coatings can be used. [Guangyuan Zheng, Qianfan Zhang,Judy J. Cha, Yuan Yang, Weiyang Li, Zhi Wei Seh, and Yi Cui (2013)Amphiphilic Surface Modification of Hollow Carbon Nanofibers forImproved Cycle Life of Lithium Sulfur Batteries. Nano Letters doi:10.1021/nl304795g]. In addition to TiO₂ on sulfur, TiS₂ coatings can beformed on sulfur.

7) Solid electrolytes for lithium batteries. E.g., LTO+5% binder as asolid electrolyte film. In an embodiment, this electrolyte gets lithiumfrom one side and release it to the other side (due to chemical gradientand electric gradient forces).

Example 2: Hybrid Membranes

In all types of batteries, such as li-ion, alkaline and lead-acid, theseparator used with the liquid electrolyte is based on electronicallyinsulating and ionically insulating polymers such as polyethylene (PE)and polypropylene (PP). Polymer electrolytes such as PEO have been triedin li-ion cells without liquid electrolyte and without a PE-PPseparator, but their ionic conductivity is too low. Polymer electrolytessuch as PEO have been tried in Li-ion cells with liquid electrolyte andwithout a PE-PP separator, but their structural stability is too low andthere is no benefit in using them. Ceramic-glass based electrolytes suchas LIPON and LISICON have been tried in li-ion cells with and withoutliquid electrolyte and without a PE-PP separator, but their ionicconductivity is too low, and their cost is too high.

In Li-ion cell with liquid electrolyte, membranes made of conventionalactive materials with different charge-discharge voltages vs Li+/Li caneffectively replace the PE-PP separators and decrease the cost of thecell, while increasing its performance and manufacturing speed. The costof separators now is about $2 per sqm, but the cost of the membranesuggested in this invention is $0.2 per sqm; further the interfaceimpedance between the PE-PP separators is much higher than that of themembrane suggested here and electrodes, which increases the rate andcycle life; it further may prevent any catastrophic failure such as firedue to the high thermal stability of the disclosed membrane. The activematerial can be initially lithiated or not. Examples of the materialsare TiO₂, TiS₂, lithium titanate, graphite, LiFePO₄. An example is a 50%porous layer, 10 micrometers thick made of 90% TiO₂ mixed with 10%binder such as PVDF. Al₂O₃ can also be added for lower interfaceresistance on the electrode-electrolyte interface, an example is a 50%porous layer, 10 micrometers thick made of 80% lithium titanate mixedwith 10% binder such as PVDF and 10% Al2O3. In some embodiments thismembrane can have several layers in which at least one of the layers mayhave high electronic conductivity. An example is a 50% porous layer, 10micrometers thick made of 80% lithium titanate mixed with 10% bindersuch as PVDF and 10% Al2O3 with a thin, a few micrometers or less,carbon coating on at least one side of it. Another example is a 50%porous layer, 10 micrometers thick made of 80% lithium titanate mixedwith 10% binder such as PVDF and 10% Al2O₃ as the first layer and a 50%porous layer, 10 micrometers thick made of 80% lithium titanate mixedwith 5% carbon black and 5% binder such as PVDF and 10% Al2O3 as thesecond layer. The electrolyte can be conventional li-ion electrolytesuch as mix of organic solvents (for example, PC, DMC, EC) and a lithiumsalt (for example, LiPF6 or LiClO₄). The electrodes can be any li-ionelectrodes such as lithium, silicon or graphite anode materials andLiFePO₄, LiCoO₂, Sulfur or Air cathode. In some embodiments, themembrane can be a coating on at least one of the electrodes. Severalexamples are A) a 5 micrometer, 50% porosity coating of 90% lithiumtitanate, 5% carbon black and 5% PVDF binder on silicon anode in ali-ion cell. B) a 5 micrometer, 50% porosity coating of 90% lithium ironphosphate, 5% carbon black and 5% PVDF binder on sulfur cathode in ali-ion cell. C) a 5 micrometer, 50% porosity coating of 90% TiO2, 5%carbon black and 5% PVDF binder on silicon anode in a li-ion cell. D) a5 micrometer, 50% porosity coating of 85% lithium titanate, 10% Al₂O₃and 5% PVDF binder on sulfur cathode in a li-ion cell. The electrolytescan be liquid such as commercial PC-EC-DMC with 1 M LiPF6, or can besolid such as LIPON, LISICON or PEO with LiPF₆.

The inventors have also found that ceramic-glass and polymerelectrolytes fortified with conventional active materials with differentcharge-discharge voltages vs Li+/Li, such as conventional anode andcathode active materials in li-ion cells, can effectively resolve themanufacturing challenges of solid electrolytes, such as low flexibilityand pinholes. Some examples are A) a li-ion solid electrolyte with 85%LISICON powder, 5% lithium titanate and 10% PVDF binder, in NMP solventmade with a slurry process. B) a li-ion solid electrolyte with 70%LISICON, 15% TiO2, 5% lithium iron phosphate, 5% carbon black and 5%PVDF binder, in NMP solvent made with a slurry process; In this case,due to the presence of the electronically conductive carbon black, aliquid electrolyte and separator or a non-electronic conductive porouscoating is needed between the membrane and at least on electrode. C) ali-ion solid electrolyte with 70% PEO with LiPF6 salet, 15% LISICON, 5%lithium titanate, 5% Al2O3 and 5% PVDF binder. D) a li-ion solidelectrolyte with 65% LISICON, 10% MnO2, 5% PEO with LiFP6, 5% Al2O3, 5%TiO2, 5% lithium titanate and 5% PVDF binder. The electrolytes can beliquid such as commercial PC-EC-DMC with 1 M LiPF6, or can be solid suchas LIPON, LISICON or PEO with LiPF6. A metallic frame, such as aluminumcopper, titanium, iron or stainless steel, can be used to provide bothelectronic conductive network in the membrane and structural stability;however the membrane should not connect the anode and cathodeelectronically, for example one interface of the membrane and anelectrode needs an electronically insulating layer.

Example 3: PEO/LiClO₄ Polymer Electrolyte Coated Seperatores

Kapton (K) separator and aluminum (Al) mesh was coated with variouscombinations of poly(ethylene) oxide (PEO) and lithium perchlorate(LiClO₄) polymer electrolyte solutions. The description andconcentrations of PEO coated separators are shown in Table 2 below.Separators that were coated with a 50:50 weight percent mixture of PEO:LiClO₄ polymer electrolyte have the highest coating weigh and separatorscoated with 5% solid PEO in H₂O have the lowest coating weight

TABLE 2 Separator PEO Combination Polymer, (PEO:LiClO) Substrate wt %LiClO₄, wt % K + PEO Kapton 100 0 K + PEO (90:10) Kapton 90 10 K + PEO(70:30) Kapton 70 30 K + PEO-50:50 Kapton 50 50 Al + PEO Al mesh 100 0Al + PEO-90:10 Al mesh 90 10 Al + PEO-70:30 Al mesh 70 30 Al + PEO-50:50Al mesh 50 50

Displayed in FIG. 13A is the SEM image of Kapton coated with PEO polymerat 89× magnification showing uniform distribution of the polymerelectrolyte coating. FIG. 13B displays a cross section of the sameseparator. It is difficult to distinguish the difference betweensubstrate and the polymer electrolyte layers for polymer electrolytethickness calculation. Better sample preparation for cross sectionimaging can done in the future, possibly using liquid nitrogen tofracture the sample more cleanly or to make use of a diamond bladecutting surface. The SEM images reveal that the pores of the separatorare not filled. Viscosity adjustment of the solution concentrationsalong with controlling the drying conditions would likely produce afully filled film. FIGS. 13C, 13D and 13E: shows additional SEM imagesof coated Kapton substrates: FIG. 13C: Kapton+PEO, FIG. 13D: Kapton+PEO:LiClO₄/90:10. FIG. 13E: Kapton+PEO: LiClO₄/50:50. FIGS. 13F, 13G and 13Hshow SEM images of coated Al substrates. FIG. 13F shows an Al substratecoated with PEO, FIG. 13G shows an Al+PEO: LiClO4/90:10, FIG. 13D showsAl+PEO: LiClO4/50:50.

Microscope images of different polymer coated separators are displayedin FIGS. 14A-14D and FIGS. 14E-14H. FIG. 14A: Kapton+PEO; FIG. 14B:Kapton+PEO: LiClO₄/90:10; FIG. 14C: Kapton+PEO: LiClO₄/70:30; FIG. 14D:Kapton+PEO: LiClO₄/50:50. FIG. 14E: Al+PEO; FIG. 14F: Al+PEO:LiClO₄/90:10; FIG. 14G: Al+PEO: LiClO₄/70:30; FIG. 14H: Al+PEO:LiClO₄/50:50.

Half cells in coin cell format with polymer electrolyte coatedseparators displayed in Table 1, lithium cobalt oxide (LCO) cathodes, Lianode, and DMC/1M LiClIO₄ electrolyte were prepared in a glovebox.

FIG. 15 above shows the average OCV measurements of these LCO half coincells. The fraction next to the name of the cell at the bottom of thebar graph represents the number of working cells yielded over the totalnumber of cells made. This figure displays the average OCV of thoseyielded cells (in Volts). In general, cells with Al mesh substratedisplayed the highest failure rate. It is possible that the Al mesh,which is thicker and more rigid than Kapton is shorting some of thecells when pressed into the coin cell format.

After OCV measurements, the internal ohmic resistance measurements weretaken for the individual coin cells. FIGS. 16 (a) and (b) shows thedefinition of the measurement elements used. FIGS. 17A-17C summarizesthe results obtained from circuit simulation of the Nyquist plot.Displayed in FIG. 17A is the relationship between coin cells withdifferent polymer coated electrolyte and R1, which is defined as theelectrolyte or ohmic resistance. (See FIGS. 16 (a) and (b)). Displayedin FIG. 17B is the relationship between coin cells with differentpolymer coated electrolyte and Q1, which is defined as the double-layercapacitance. Finally, displayed in FIG. 17C is the relationship betweencoin cells with different polymer coated electrolyte and R2, which isthe polarization resistance.

In general, the relationship between R1, R2 and Q1 are inverselyproportional and this trend can be seen from the data. The increase inR1 or R2 indicates internal resistance increases inside of the cell. Inthis case all the coin cells were made the same way, with the onlycomponent that is variable is the different polymer electrolytes coatedon different substrates. Therefore, the internal resistance can beattributed to the different polymer electrolytes on the substrates. Itis difficult to conclude from the data which polymer electrolyte coatedseparator is the best without further investigation into optimizedcoating parameters, but generally, cells with Al mesh as a substrateshow lower RA, R2 and higher Q1 in comparison to other cells. This couldbe due to conductivity of the Al mesh. The overlaid Nyquist plots of thedata shown in FIGS. 17A-17C are displayed in FIG. 18, In the legend forFIG. 18, the identifier Al-50-50-PEO-4_03_GBS_C01.mpr: −Im(z) vs. Re(Z)has been abbreviated as Al-50-50-PEO; the identifierAl-90-10-PEO-3_02_GBS_C01.mpr: −Im(z) vs. Re(Z) has been abbreviated asAl-90-10-PEO; the identifier 90-10-PEO-1_02_GBS_C01.mpr: −Im(z) vs.Re(Z) has been abbreviated as 90-10-PEO; the identifierAl-50-50-PEO-4_03_GBS_C01.mpr: <Ew e> vs. Re(Z) has been abbreviated asAl-50-50-PEO Ew e vs. Re(Z); the identifier Al-PEO-5_03_GBS_C01.mpr:−Im(z) vs. Re(Z) has been abbreviated as Al-PEO; the identifierCelgard-3_03_GBS_C01.mpr: −Im(z) vs. Re(Z)# has been abbreviated asCelgard; the identifier Al-70-30-PEO-1_02_GBS_C01.mpr: <Ew e> vs. Re(Z)has been abbreviated as Al-70-30-PEO Ew e vs. Re(Z); the identifierK-50-50-PEO-4_02_GBS_C01.mpr: −Im(z) vs. Re(Z) has been abbreviated asK-50-50-PEO; the identifier Al-70-30-PEO-1_02_GBS_C01.mpr: −Im(z) vs.Re(Z) has been abbreviated as Al-70-30-PEO and the identifierK-70-30-PEO-3_02_GBS_C01.mpr: −Im(z) vs. Re(Z) has been abbreviated asK-70-30-PEO.

Results of 1^(st) cycle electrochemical data is displayed in FIG. 19below. FIG. 19 shows the first cycle charge capacity, discharge capacityand percent retention of the coin cells with different polymerseparators. The charge capacity indicated by the left hand column andthe discharge capacity indicated by the right hand column are plotted onthe Y1 axis (left side) and the percent retention of the charge capacityindicated by the curve is plotted on Y2 axis (right side).

The cells were charged at C/10 to 4.2V and discharged at a rate of C/10to 2.5 V. The designed capacity for the cells were 6 mAh and on anaverage 5 mAh were extracted. Generally, cells with Kapton separatorperformed better then cells with Al mesh. Cells with Kapton coated withPEO showed the best results. Cells with Kapton: PEO: 90:10 type ofpolymer separator were selected for further cycling.

Shown in FIG. 20A is the charge capacity cycle life comparison of cellswith PEO: 90:10 configuration of polymer electrolyte coated on Kaptonand Al mesh against control cell. Control cells display higher capacitythrough 4 cycles. No difference is observed between polymer electrolytescoted on Kapton or Al mesh. Shown in FIG. 19B is the discharge capacitycycle life comparison of cell with PEO: 90:10 configuration of polymerelectrolyte coated on Kapton and Al mesh against the control cell.Polymer electrolyte coated in Al had slightly higher discharge capacitythan polymer coated on Kapton. At this time in the experiment, morecycle data is needed to draw a firm conclusion that this performs betterthan the control cell however.

FIG. 20A-20B: shows the cycle life of cells. First cycle with PEO:90:10configuration coated on Kapton and Al mesh. FIG. 20A. Charge cycle. FIG.20B. Discharge cycle.

Example 4 PVDF Polymer Base Slurry Coated on Supports

Kapton (K) separator and aluminum (Al) mesh were coated with variouscombinations of slurry made of Polyvinylidene fluoride (PVDF),Lithium-titanate (LTO), Carbon Filler (CF) and Graphite (G). Thedescriptions and concentrations of these PVDF based slurry coatedseparators are displayed in Table 3 below.

TABLE 3 PVDF Binder Active Separator Formulation Amount MaterialConductive Name Substrate wt % wt % Filler wt % K + PVDF Kapton 100 0 0K + PVDF + LTO Kapton 30 60 10 K + PVDF + LTO + CF Kapton 35 65 0 K +PVDF + G Kapton 35 65 0 AL + PVDF Al mesh 100 0 0 AL + PVDF + LTO Almesh 30 60 10 AL + PVDF + LTO + CF Al mesh 35 65 0 AL + PVDF + G Al mesh35 65 0 . . .

The coating weights per area of these separators are displayed in FIG.21. PVDF slurry coated on Al substrates gave higher coating weights onaverage, with the formulation of PVDF with Graphite giving the highestcoating loading within the group of tests. Weights are in g/cm².

Microscope images of substrates coated with PVDF base slurries: FIG.22A: Kapton coated with PVDF and LTO slurry. FIG. 22B: Kapton coatedwith PVDF, LTO, and CF slurry. FIG. 22C: Kapton coated with PVDF, andgraphite slurry. FIG. 22D: Al mesh coated with PVDF and LTO slurry. FIG.22E: Al mesh coated with PVDF, LTO and CF slurry. FIG. 22F: Al meshcoated with PVDF, and graphite slurry.

The microscope images of these Kapton and Al mesh coated PVDF basedslurry in FIGS. 22A-22F show that on both substrates the slurry coatedwith PVDF and graphite formulation covers the surfaces more smoothly anduniformly in comparison to coatings with PVDF and LTO slurry. Roughsurfaces can result in micro shorts during the coin cell assembly. FIGS.22A-22F also shows that with manipulation of the slurry viscosity it ispossible to fill in the all the pores of the substrate. Furtherexperiments can be conducted. The PVDF polymer can fill in the holescompletely at the current dimensions as can be seen in FIG. 23D and SEMimage of FIG. 23 showing Al mesh coated with PVDF.

FIGS. 24A and 24B show SEM images of Al (FIG. 24A) mesh and Kapton (FIG.24B) coated with PVDF and graphite slurry.

Displayed in FIGS. 24A and 24B are Kapton and Al mesh coated with PVDFand graphite slurry with an edge on view. It is difficult to distinguishthe difference between substrate and the polymer electrolyte layers forprecise thickness calculations but the overall thickness isapproximately 20 microns. Fracturing of the samples using liquidnitrogen for end on analysis or cutting with a diamond blade shouldprovide more exact dimensional details in the future should that beneeded.

Half cells in coin cell format were prepared in a glovebox using thesePVDF polymer based slurry coated separators, LCO cathodes, Li anodes,and two different electrolytes (EC/DMC with 1M LiPF₆ and DMC with 1MLiPF₆).

FIG. 25 shows average open circuit voltage (OCV) measurements of the LCOhalf coin cells made with PVDF base slurries. The fraction next to thename of the cell represents the number of working cells yielded over thetotal number of cells attempted. The figure displays the average OCV involts of the working cells. Overall, all the cells had low OCV and theyields of functioning coin cells were relatively low. This wasattributed to use of two different types of electrolyte. Coin cellmechanics, cathode electrode (punched edges), quality of Li and crimperalso can contribute to bad yield.

After OCV measurements were taken, the internal ohmic resistancemeasurements were recorded for individual coin cells. FIGS. 26A-26Csummarize the results obtained from circuit simulation of the Nyquistplot. Displayed in FIG. 26A is the relationship between coin cells withdifferent polymer coated electrolytes and R1, which is defined as theelectrolyte or ohmic resistance. (See FIGS. 16 (a) and (b)). Displayedin FIG. 26B is the relationship between coin cells with differentpolymer coated slurry and Q1, which is defined as the double-layercapacitance. Finally, displayed in FIG. 26C is the relationship betweencoin cells with different polymer coated electrolyte and R2, which isdefined as the polarization resistance.

In general, relationship between R1, R2 and Q1 are inverselyproportional. The increase in R1 or R2 indicates internal resistanceincreases inside of the cell. In this case all the coin cells wereattempted to be made the same way, with the only component that waschanged was the different polymer electrolytes coated on differentsubstrates in theory. Therefore, the internal resistance differences canbe attributed to the different polymer electrolytes substrates used. Itis difficult to conclude from this initial data which polymerelectrolyte coated separator is the best performing. As can be seen inoverlaid Nyquist plot in FIG. 27 the data was very inconsistent. Theseinconsistent results could have been a result of two differentelectrolyte lots that were needed to complete the series of experiments.Ideally no other changes would have been made during the assembly ofthese cells. However, the coin cell spacers and the springs were changedthrough the series of builds and so drawing a firm conclusion from onecell to the next is not reliable. To get a reliable data it is importantto the experiments consistent with only one variable changed at a time.It is recommended that these results obtained are repeated. In thelegend for FIG. 27, the identifier Al-PVdf-1_02_GBS_C01.mpr has beenabbreviated as Al-PVdf; the identifier K-PVDF-LTO-3_03_GBS_C01.mpr hasbeen abbreviated as K-PVDF-LTO; the identifier ctl-2_02_GBS_C01.mpr hasbeen abbreviated as ctl-2; the identifier K-PVDF-G-2_03_GBS_C01.mpr hasbeen abbreviated as K-PVDF-G; the identifierAl-PVDF-LTO-3_03_GBS_C01.mpr has been abbreviated as Al-PVDF-LTO; theidentifier K-PVdf-LTO-CF-2_02_GBS_C01.mpr has been abbreviated asK-PVdf-LTO_CF; the identifier Al-PVDF-LTO-CF-2_03_GBS_C01.mpr has beenabbreviated as Al-PVDF-LTO-CF; the identifier K-PVdf-1_02_GBS_C01.mprhas been abbreviated as K-PVdf; and the identifierAl-PVDF-G-3_03_GBS_C01.mpr has been abbreviated as Al-PVDF-G.

Due to the number of Arbin channels available, only the PVDF andgraphite slurry coated Kapton and Al mesh cell were selected to becycled. The electrochemical data displayed in FIG. 28 is of those cells,where the 1^(st) cycle is shown. FIG. 28: First cycle charge capacity,discharge capacity, and percent retention of the coin cells with Kaptonand Al mesh coated with PVDF and graphite slurry. The charge capacityindicated by the left column and the discharge capacity indicated by theright column are plotted on the Y1 axis (left side) and the percentretention of the charge capacity indicated with by the curve is plottedon Y2 axis (right side).

The cells were charged at C/10 to 4.2V and discharged at rate of C/10 to2.5 V. The designed capacity for the cells was calculated to be 6 mAhand on an average 5 mAh was extracted from these cells. The earlyresults show that cells with Al substrate displayed the lowest percentretention at 66%, in comparison to cells with the Kapton substrate at97%.

Shown in FIG. 29A is the charge capacity cycle life comparison of cellswith K+PVDG+G, Al+PVDF+G, and the control separator. Other than theinitial drop in charge capacity there is no difference that can yet beobserved between polymer electrolytes coated on Kapton or Al mesh in thecycle history. This will continue to be monitored over time forvariations. Shown in FIG. 29B is the discharge capacity cycle lifecomparison of cell with K+PVDG+G, Al+PVDF+G and the control separator.At this time, more cycles are still needed for any conclusions to bedrawn and the cycling will continue.

STATEMENTS REGARDING INCORPORATION BY REFERENCE AND VARIATIONS

All references throughout this application, for example patent documentsincluding issued or granted patents or equivalents; patent applicationpublications; and non-patent literature documents or other sourcematerial; are hereby incorporated by reference herein in theirentireties, as though individually incorporated by reference, to theextent each reference is at least partially not inconsistent with thedisclosure in this application (for example, a reference that ispartially inconsistent is incorporated by reference except for thepartially inconsistent portion of the reference).

All patents and publications mentioned in the specification areindicative of the levels of skill of those skilled in the art to whichthe invention pertains. References cited herein are incorporated byreference herein in their entirety to indicate the state of the art, insome cases as of their filing date, and it is intended that thisinformation can be employed herein, if needed, to exclude (for example,to disclaim) specific embodiments that are in the prior art. Forexample, when a compound is claimed, it should be understood thatcompounds known in the prior art, including certain compounds disclosedin the references disclosed herein (particularly in referenced patentdocuments), are not intended to be included in the claim.

When a group of substituents is disclosed herein, it is understood thatall individual members of those groups and all subgroups and classesthat can be formed using the substituents are disclosed separately. Whena Markush group or other grouping is used herein, all individual membersof the group and all combinations and subcombinations possible of thegroup are intended to be individually included in the disclosure. Asused herein, “and/or” means that one, all, or any combination of itemsin a list separated by “and/or” are included in the list; for example“1, 2 and/or 3” is equivalent to “‘1’ or ‘2’ or ‘3’ or ‘1 and 2’ or ‘1and 3’ or ‘2 and 3’ or ‘1, 2 and 3’”.

Every formulation or combination of components described or exemplifiedcan be used to practice the invention, unless otherwise stated. Specificnames of materials are intended to be exemplary, as it is known that oneof ordinary skill in the art can name the same material differently. Oneof ordinary skill in the art will appreciate that methods, deviceelements, starting materials, and synthetic methods other than thosespecifically exemplified can be employed in the practice of theinvention without resort to undue experimentation. All art-knownfunctional equivalents, of any such methods, device elements, startingmaterials, and synthetic methods are intended to be included in thisinvention. Whenever a range is given in the specification, for example,a temperature range, a time range, or a composition range, allintermediate ranges and subranges, as well as all individual valuesincluded in the ranges given are intended to be included in thedisclosure.

As used herein, “comprising” is synonymous with “including,”“containing,” or “characterized by,” and is inclusive or open-ended anddoes not exclude additional, unrecited elements or method steps. As usedherein, “consisting of” excludes any element, step, or ingredient notspecified in the claim element. As used herein, “consisting essentiallyof” does not exclude materials or steps that do not materially affectthe basic and novel characteristics of the claim. Any recitation hereinof the term “comprising”, particularly in a description of components ofa composition or in a description of elements of a device, is understoodto encompass those compositions and methods consisting essentially ofand consisting of the recited components or elements. The inventionillustratively described herein suitably may be practiced in the absenceof any element or elements, limitation or limitations which is notspecifically disclosed herein.

The terms and expressions which have been employed are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms and expressions of excluding any equivalents of thefeatures shown and described or portions thereof, but it is recognizedthat various modifications are possible within the scope of theinvention claimed. Thus, it should be understood that although thepresent invention has been specifically disclosed by preferredembodiments and optional features, modification and variation of theconcepts herein disclosed may be resorted to by those skilled in theart, and that such modifications and variations are considered to bewithin the scope of this invention as defined by the appended claims.

The invention claimed is:
 1. An electrochemical cell comprising: apositive electrode comprising a positive electrode active material and afirst current collector in electronic communication with the positiveelectrode active material, the first current collection furthercomprising a first external connection tab; a negative electrodecomprising a negative electrode active material and a second currentcollector in electronic communication with the negative electrode activematerial, the second current collector further comprising a secondexternal connection tab; a composite membrane disposed between thepositive electrode and the negative electrode; the composite membranebeing ionically conductive and comprising: an active layer; wherein saidactive layer comprises an ionically conductive solid-state material; afirst ionically conductive separator positioned between the positiveelectrode and the ionically conductive solid-state material; and asecond ionically conductive separator positioned between the negativeelectrode and the ionically conductive solid-state material; wherein thecomposite membrane further comprises a third external connection tab inelectronic communication with the ionically conductive solid-statematerial; and one or more electrolytes positioned between said positiveelectrode and said negative electrode; said one or more electrolytescapable of conducting ionic charge carriers; said one or moreelectrolytes including at least one liquid electrolyte disposed betweenthe composite membrane and the positive electrode, the negativeelectrode or both the positive and negative electrodes; wherein saidionically conductive solid-state material is in electronic communicationwith said third external connection configured to electronicallyactivate said ionically conductive solid-state material so as to providefor an increase in the ionic conductivity of said ionically conductivesolid-state material in response to application of a voltage or currentbetween said ionically conductive solid-state material and one of saidpositive electrode and said negative electrode using said third externalconnection.
 2. The electrochemical cell of claim 1, wherein theionically conductive solid-state material is in the form of a sheet, thesheet being substantially nonporous.
 3. The electrochemical cell ofclaim 2, wherein the ionically conductive solid-state material is fromto 10 nm to 50 μm in thickness.
 4. The electrochemical cell of claim 1,wherein the ionically conductive solid-state material comprises amixture of ionically conductive particles and electronically conductiveparticles.
 5. The electrochemical cell of claim 1, wherein the ionicallyconductive solid-state material is configured to be selectivelyelectronically connected to and disconnected from the negativeelectrode.
 6. The electrochemical cell of claim 1, wherein the ionicallyconductive solid-state material is configured to be selectivelyelectronically connected to and disconnected from the positiveelectrode.
 7. The electrochemical cell of claim 1, wherein the ionicallyconductive solid-state material is electrochemically active.
 8. Theelectrochemical cell of claim 1, wherein the ionically conductivesolid-state material is a solid or gel comprising a material selectedfrom the group consisting of carbon, lithium titanate, Li₂O₂, Li₂O,titanium disulfide, iron phosphate, SiO2, V₂O₅, lithium iron phosphate,MnO₂, Al₂O₃, TiO₂, LiPF₆, Li₃P, Li₃N, LiNO₃, LiClO₄, LiOH, PEO, P₂O₅,LIPON, LISICON, ThioLISICO, Ionic Liquids, Al, Cu, Ti, Stainless Steel,Iron, Ni, graphene oxide, PEDOT-PSS, and combinations thereof.
 9. Theelectrochemical cell of claim 1, wherein the electrochemical cell is aLi-ion or Na-ion cell.
 10. The electrochemical cell of claim 1, whereinsaid first ionically conductive separator is porous or perforated andwherein said second ionically conductive separator is porous orperforated.
 11. The electrochemical cell of claim 1, wherein theconductivity of said ionically conductive solid-state material islithium titanate.
 12. An electrochemical cell comprising: a positiveelectrode; a negative electrode; a composite membrane layer positionedbetween the said electrodes comprising: an active layer; wherein saidactive layer comprises at least one ionically conductive solid-statematerial; wherein the composite membrane further comprises a thirdexternal connection tab in electronic communication with the ionicallyconductive solid-state material; at least one ionically conductiveseparator positioned between the positive electrode or negativeelectrode and the ionically conductive solid-state material; and one ormore electrolytes positioned between said positive electrode and saidnegative electrode; said one or more electrolytes capable of conductingionic charge carriers; said one or more electrolytes including at leastone liquid electrolyte disposed between the composite membrane layer andthe positive electrode, the negative electrode or both the positive andnegative electrodes; wherein said at least one ionically conductivesolid-state material is in electronic communication with said thirdexternal connection configured to electronically activate said ionicallyconductive solid-state material activatable so as to provide for anincrease in the ionic conductivity of said ionically conductivesolid-state material in response to application of a voltage or currentbetween said external connection tab and one of said positive electrodeand said negative electrode using said third external connection. 13.The electrochemical cell of claim 12, wherein the at least one ionicallyconductive solid-state material is in the form of a coating on at leastone side of one of the electrodes.
 14. The electrochemical cell of claim12, wherein the composite membrane layer is from 10 nm to 50 μm inthickness.
 15. The electrochemical cell of claim 12, wherein the atleast one ionically conductive solid-state material has voltage rangesof reduction and oxidation, with values between the charge-dischargevoltage limits of the said electrochemical cell.
 16. The electrochemicalcell of claim 12, wherein the at least one ionically conductivesolid-state material comprises a material selected from the groupconsisting of carbon, lithium titanate, Li₂O₂, Li₂O, titanium disulfide,iron phosphate, SiO2, V₂O₅, lithium iron phosphate, MnO₂, Al₂O₃, TiO₂,LiPF₆, Li₃P, Li₃N, LiNO₃, LiClO₄, LiOH, PEO, P₂O₅, LIPON, LISICON,ThioLISICO, Ionic Liquids, Al, Cu, Ti, Stainless Steel, Iron, Ni,graphene oxide, PEDOT-PSS, and combinations thereof.
 17. Theelectrochemical cell of claim 12, wherein the electrochemical cell is aLi-ion or Na-ion cell.
 18. The electrochemical cell of claim 12, whereinthe at least one ionically conductive solid-state material is in theform of a coating on at least one side of one of an ionically conductiveseparator.
 19. The electrochemical cell of claim 12, wherein theionically conductive solid-state material is electrochemically active.20. The electrochemical cell of claim 12, wherein the composite membranelayer comprises at least one solid-state binder material.
 21. Theelectrochemical cell of claim 12, wherein the composite membrane layeris porous.
 22. The electrochemical cell of claim 12, wherein the atleast one ionically conductive separator is porous or perforated. 23.The electrochemical cell of claim 12, wherein the conductivity of saidionically conductive solid-state material is lithium titanate.
 24. Amethod for operating an electrochemical cell comprising steps of:providing an electrochemical cell, the cell comprising: a positiveelectrode comprising a positive electrode active material and a firstcurrent collector in electronic communication with the positiveelectrode active material, the first current collection furthercomprising a first external connection tab; a negative electrodecomprising a negative electrode active material and a second currentcollector in electronic communication with the negative electrode activematerial, the second current collector further comprising a secondexternal connection tab; a composite membrane disposed between thepositive electrode and the negative electrode; the composite membranebeing ionically conductive and comprising: an active layer; wherein saidactive layer comprises an ionically conductive solid-state material; athird external connection in electronic communication with saidionically conductive solid-state material; a first ionically conductiveseparator positioned between the positive electrode and the ionicallyconductive solid-state material; and a second ionically conductiveseparator positioned between the negative electrode and the ionicallyconductive solid-state material; and one or more electrolytes positionedbetween said positive electrode and said negative electrode; said one ormore electrolytes capable of conducting ionic charge carriers; said oneor more electrolytes including at least one liquid electrolyte disposedbetween the composite membrane and the positive electrode, the negativeelectrode or both the positive and negative electrodes; and applying avoltage or current between said ionically conductive solid-statematerial and one of said positive electrode and said negative electrodeusing said third external connection, thereby increasing an ionicconductivity of said ionically conductive solid-state material.
 25. Themethod of claim 24, wherein the conductivity of said ionicallyconductive solid-state material is lithium titanate.
 26. A method foroperating an electrochemical cell comprising steps of: providing anelectrochemical cell, the cell comprising: a positive electrode; anegative electrode; a composite membrane layer positioned between thesaid electrodes comprising: an active layer; wherein said active layercomprises at least one ionically conductive solid-state material inelectronic communication with an external connection tab; at least oneionically conductive separator positioned between the positive electrodeor negative electrode and the ionically conductive solid-state material;a third external connection in electronic communication with saidionically conductive solid-state material; and one or more electrolytespositioned between said positive electrode and said negative electrode;said one or more electrolytes capable of conducting ionic chargecarriers; said one or more electrolytes including at least one liquidelectrolyte disposed between the composite membrane layer and thepositive electrode, the negative electrode or both the positive andnegative electrodes; and applying a voltage or current between saidionically conductive solid-state material and one of said positiveelectrode and said negative electrode using said third externalconnection, thereby increasing an ionic conductivity of said ionicallyconductive solid-state material.
 27. The method of claim 26, wherein theconductivity of said ionically conductive solid-state material islithium titanate.